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New methods and data sources for measuring economic consequences of workplace injuries.

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AMERICAN JOURNAL OF INDUSTRIAL MEDICINE 40:452±463 (2001)
New Methods and Data Sources for
Measuring Economic Consequences
of Workplace Injuries
Robert T. Reville, PhD, Jayanta Bhattacharya,
Lauren R. Sager Weinstein, AB
MD, PhD,
and
Background Evaluation of programs and policies to reduce the incidence of workplace
injuries require that the consequences of injury are estimated correctly. Because
workplace injuries are complex events, the availability of data that re¯ects this
complexity is the largest obstacle to this estimation.
Methods We review the literature on the consequences of workplace injuries for both
workers and employers, focusing on data sources, particularly linked administrative data
from different public agencies. We also review other approaches to obtaining data to
examine workplace injuries, including public-use longitudinal survey data, primary data
collection, and linked employee-employer databases. We make suggestions for future
research.
Results Recent advances in the literature on the economic consequences of workplace
injuries for workers have been driven to a great extent by the availability of new data
sources. Much remains unexplored. We ®nd longitudinal survey databases including the
National Longitudinal Survey of Youth, and the Health and Retirement Survey, to be very
promising though largely untapped sources of data on workplace injuries. We also ®nd
that linked employee-employer databases are well suited for the study of consequences
for employers.
Conclusions We expect that new data sources should lead to rapid advances in our
understanding of the economic consequences of workplace injuries for both workers and
employers. Am. J. Ind. Med. 40:452±463, 2001. ß 2001 Wiley-Liss, Inc.
KEY WORDS: economic consequences; wage losses; employer costs; administrative
data
INTRODUCTION
Workplace injuries and illnesses impose signi®cant
economic costs upon society. Fatalities are the most
dramatic measure of the losses from workplace injuries;
RAND, 1700 Main Street, PO Box 2138, Santa Monica, California 90407-2138
This paper was first presented at the NIOSH conference, ``Functional, Economic, and
Social Outcomes of Occupational Injuries and Illnesses: Integrating Social, Economic, and
Health Services Research'', Denver, CO, June13^15, 1999.
*Correspondence to: Robert T. Reville, RAND, PO Box 2138, Santa Monica, CA,
90407-2138.
Accepted 22 May 2001
ß 2001Wiley-Liss, Inc.
according to the Bureau of Labor Statistics's (BLS) Census
of Fatal Occupational Injuries (CFOI), 6,218 fatalities
occurred at work as a result of an injury in the US in
1997. Mortality from occupational illnesses are much harder
to measure, as discussed in Leigh et al. [2000], who
estimates over 60,000 deaths in 1992. However, fatal
injuries and illnesses are a minute fraction of all workplace
injuries. In 1997, according to the BLS Annual Survey of
Occupational Injuries and Illnesses, 6.1 million workplace
injuries and illnesses occurred nationally, and 2.9 million of
these resulted in time out of work (lost-time injuries). All of
these injuries potentially impose costs on employers,
workers and their families, or both. But how large are the
Economic Consequences of Workplace Injuries
costs and how does one go about measuring them? These
questions are fundamental to any policy evaluation, since
economic costs are a key outcome measure.
In this discussion, we describe some analytical and
methodological issues, new data sources and new
approaches to constructing databases for the estimation of
the consequences of workplace injuries. A recent study by
Leigh et al. [2000] discusses many of the methodological
issues in estimating incidence and costs of workplace
injuries and data limitations with many of the commonly
used databases. We do not attempt to repeat that information
here. Our purpose is to describe new methods and data
sources, rather than to review comprehensively the older
literature and data.
We summarize data sources available for workplace
injury research, discuss the estimation of losses to workers,
focusing on the growing literature on wage loss due to injury
and describe the estimation of employer costs, noting the
paucity of research in the area, and ®nally make suggestions
for research and data collection.
Data for Measuring Losses from
Workplace Injuries
A number of studies have calculated the total annual
costs from workplace injuries by summing and combining
multiple data sources or workers' compensation administrative databases. These include Miller [1995, 1997] and
Leigh et al. [1997, 2000] the letter includes a detailed review
of this literature. These studies rely upon many assumptions
and extrapolations from estimates of particular costs faced
by workers or employers. The data and methods for the
component costs of these extrapolations are often quite
¯awed or limited. As these authors recognize, to the extent
these aggregations rely upon poorly estimated component
costs, the reliability of the aggregate estimates are also
limited. More importantly, accurate estimates of the
employer or worker costs are also critical for assessment
of the adequacy and equity of workers' compensation
bene®ts, evaluations of safety programs, return to work
programs, or other interventions.
Several types of data sources are available for research
on worker and employer costs. Leigh et al. [2000] evaluates
(and generally ®nds wanting) several of the better known
databases, including the BLS's CFOI, NIOSH's National
Traumatic Occupational Fatality Study (NTOF), BLS's
Annual Survey of Occupational Injuries and Illnesses, the
National Health Interview Survey (NHIS), and the National
Council on Compensation Insurance (NCCI) Ultimate
Reports. In addition to these data sources, there are a
number of less common but arguably more satisfactory
alternatives, including primary data collection, public-use
survey databases other than the NHIS, and linked administrative data.
453
Primary data collection
Several characteristics of workplace injuries complicate primary data collection on costs:
*
*
Workplace injuries are complex events. Losses from
workplace injuries may occur over many years or an
entire lifetime. Payments of costs associated with the
injury may be made by both workers and employers,
may change over time, and may be dif®cult to
differentiate from costs that would have occurred even
if the injury had not occurred. Losses for the same
injury may differ by socio-economic and demographic
characteristics of the worker, economic conditions at
the time of the injury, and characteristics of the
employer
In terms of annual incidence in the population,
workplace injuries are relatively rare events. In 1996,
according to U.S. Census Bureau [1997], there were 98
million households in the US. Using the BLS annual
incidence estimate, an individual household has an
injury propensity for lost-time injuries of about .03
assuming no more than one lost-time injury or illness per household. Consequently, to collect a sample
of 300 workers with workplace injuries in a given
year, a survey would need to contact 10,000 households.
Data for rare events usually require large sample sizes.
But survey data for complex events usually need to be
detailed, and in order to be affordable, these surveys
typically have small sample sizes. For instance, they may
require longitudinal data for the same individual, and long
questionnaires. The net result is that frequently, surveys
with detailed information on certain aspects of rare and
complex events may lack information fundamental to
analyzing the event. For instance, the NHIS 1994±1995
Disability Supplement, which includes detailed information
on the consequences of disability, has very limited labor
force information and does not include information about
workers' compensation bene®ts received.
Primary data collection on the scale required is rarely
an option. One study that collected primary data at the
household level is Hensler et al. [1991]. In this study, 26,000
households were contacted in an initial screener, and 2,770
with accidental injuries (including those in the workplace)
were administered a detailed interview. The sampling
frame included individuals who experienced injuries over
several prior years and at least some costs (medical or time
loss) in the previous year. It also included individuals
with workplace injuries who did not ®le workers' compensation claims. The population prevalence of workplace
injuries was .044. Despite the scale of this project, the
number of workplace injuries is still relatively small
454
Reville et al.
for many analyses, and only a single cross-section is
available.1
Since large-scale primary data collection is rarely an
option, most primary data collection on the costs of
occupational injuries and illnesses uses data collected from
a particular worksite or a limited number of ®rms. The
generalizability of these kinds of studies is always a
question.
Public-use survey data
Some surveys collected for general demographic,
health, or labor force information have longitudinal data
on labor force participation and earnings as well as extensive information on disability and workers' compensation. In general, these databases have been underutilized by
researchers interested in occupational health and safety.
Given the complexity of the impact of a workplace injury,
these databases can provide the information necessary to
estimate costs in a much more effective and affordable
manner than primary data collection.
Perhaps pre-eminent among these longitudinal data sets
(though not for occupational injury research) is the Panel
Study of Income Dynamics (PSID), which has been
collected since 1968. The drawbacks to using the PSID
for estimating the costs of injuries to workers are
considerable and also shared with many other databases.
There is minimal medical information, a relatively small
sample size, no ability to relate disability information to a
potential occupational source, and a limitation of workplace injury information to workers' compensation bene®ts
received (which signi®cantly understates injuries). The only
study related to occupational injuries and illnesses that we
are aware of using the PSID is Leigh [1985].
Other databases are more promising than the PSID. One
source of data that has not been frequently tapped for
analysis of workplace injuries is the Current Population
Survey (CPS), which is nationally representative and has
considerably larger sample sizes. As with the PSID, though,
injury information is limited to workers' compensation, and
disability information is not linked to work-relatedness.
Medical information is also limited. In addition, the
longitudinal dimension of the CPS is limited to two years.
Even with the larger sample, though, sample sizes of
occupational injuries are still an issue. For example,
Krueger [1990] uses two linked years of CPS data to
identify new workers' compensation claims and, therefore,
has only 290 workers' compensation claimants. Hirsch et al.
[1997] adopt the Krueger approach pooled across fourteen
years, yielding 1,594 workers' compensation claimants.
1
The collected data was recently used by Marquis and Manning [1999], and is
available for public use, but has not been used in any other studies of which we
are aware.
The most promising databases are the Health and
Retirement Survey (HRS), National Longitudinal Survey of
Youth (NLSY), and the Survey of Income and Program
Participation (SIPP). The HRS, which provides longitudinal
data on a sample of individuals approaching retirement age,
provides detailed information on disability, modi®ed work,
work-relatedness of disability as well as exposure to workplace hazards. It also includes extensive demographic,
®nancial, and labor market information. To our knowledge,
it has not been used for the measurement of the costs of
injuries [though it has been used to study risk factors for
injuries by Zwerling et al. [1996, 1998]. The latest wave of
the Health and Retirement Survey contains over 30,000
individuals born before 1948 and their spouses.
The NLSY collects extensive longitudinal labor market,
income, and demographic information on young people
aged 14±22 in 1979. In 1988, it began collecting extensive
information on occupational injuries and illnesses. The
NLSY data are unique among national public-use databases
in that the questions about injuries and illnesses are not
dependent upon self-report of disability or of workers'
compensation receipt. For this reason, it is the only national
survey that would allow analysis of all workplace injuries,
including nondisabling and unclaimed injuries.
While the SIPP does not have as extensive information
as the HRS or the NLSY, it is not limited to a particular age
group, has a large sample size, detailed information on
disability that can be identi®ed as work-related, and
extensive demographic, labor market and income data. We
are not aware of any research that uses this database to study
occupational injuries and illnesses.
The Appendix presents information in widely available
national public-use databases for research on workplace
injuries. The typical limitation in these databases is that
workplace injuries are identi®ed either through workers'
compensation (thereby excluding unclaimed injuries) or
through work-limiting disability (thereby typically excluding injuries that are non-disabling as of the interview date).
If the question of whether a disability results from a
workplace injury could be added to national surveys that
include disability information (as is done in the NHIS, HRS,
and SIPP), the ability to study the impact of workplace
injuries on workers would be improved. Alternatively, for
those surveys that only identify workplace injuries through
workers' compensation (such as the PSID and the CPS), the
information would be improved if individuals were asked if
they experienced an injury in the last year for which
workers' compensation were not received.
Administrative data
An alternative to survey data is workers' compensation
administrative data and OSHA logs, which serve as the
primary data source for information on injured workers in
Economic Consequences of Workplace Injuries
many studies. The data from OSHA logs are surveyed in the
BLS Annual Survey, which is reviewed by Leigh et al.
[2000]. The main advantages of workers' compensation
administrative data are that state governments and insurance
companies already collect them, they often contain detailed
information on the progress of a claim through the workers'
compensation system and on the injury, and the population
of claims is available instead of only a sample.
However, there are several disadvantages of workers'
compensation administrative data. First is that information
on injuries that do not result in claims is unavailable.
According to Hensler et al. [1991] and Biddle and Roberts
[1999], as many as 40% of workplace injuries do not result
in workers' compensation claims. Therefore, both incidence
and costs will be signi®cantly underestimated by workers'
compensation data. A second problem is that the amount of
demographic information about the injured worker is
limited. Third, these data sets include limited outcome
measures, only rarely going beyond bene®ts paid. Finally,
for workers, these data only collect information on
compensated time out of work, which misses the waiting
period for bene®ts that is required in every state, and also
misses all subsequent uncompensated time out of work
(discussed further below).
Linking across different administrative databases or
surveying workers using a sampling frame drawn from an
administrative source can correct many of the limitations
of workers' compensation administrative data. The most
common linked administrative data in recent workplace
injury research are claims data linked to wage data. These
are the data used in the wage-loss studies discussed further
below. Expanding on the links in these databases can
provide considerably more information about the consequences of workplace injuries. Links to data from other
disability programs, such as Social Security, or links to
public use databases, such as the Census or CPS, can
provide additional covariates as well as outcomes for
analysis.
Besides the wage-loss literature, Biddle and Roberts
[1999] and Biddle et al. [1998] provide additional examples
of studies that use these types of data. Both demonstrate that
a signi®cant number of workplace injuries and illnesses do
not result in workers' compensation claims. This ®nding
would clearly not be possible from workers' compensation
administrative data alone. Biddle et al. [1998] link the
Michigan Occupational Disease Reports (ODR), a database
of occupational diseases collected independently from
workers' compensation, to the Michigan Bureau of Workers' Disability Compensation data. Using the ODR as the
sampling frame, Biddle and Roberts [1999] survey workers
with occupational diseases to determine if they ®led
workers' compensation claims.
The main impediment to linking is that many of these
data sets are con®dential and distributed among several
455
different bureaucracies within states and the federal
government or are considered proprietary data by insurance
companies that collect them. If worker and corporate
con®dentiality issues can be addressed, and coordination
established across the keepers of these data, signi®cant
advances in workplace injury research will be possible.
Measuring the Economic Consequences
for Workers
By all indications, workers face considerable losses
from injury. For example, for women with indemnity claims
in Wisconsin in 1989±90, Boden and Galizzi [1999a]
estimate average 10-year pre-tax wage losses of $10,841.
Reville [1999] ®nds that a 1991±1992 sample of seriously
injured workers with permanent disability claims for
workers' compensation experienced average before-tax
wage losses of $23,692 over the ®ve years after the injury;
the most seriously disabled lost $90,793 in that same period.
Marquis and Manning [1999] estimate the life-time costs of
non-disabling workplace injuries as $10,032 and disabling
injuries as $31,183. According to Leigh et al. [2000], lost
earnings constitute one-half of the total losses from
workplace injuries. Accurate estimation of these costs is
arguably the most important task in the estimation of the
economic consequences of workplace injuries, both for
surveillance and accounting purposes, and for evaluation of
programs and interventions.
If only workers' compensation administrative data are
available, the typical approach to estimating the economic
consequences of a workplace injury for the worker has been
to examine the number of lost workdays with compensationÐthe duration of temporary disability bene®ts. This is
a common outcome measure used in the evaluation of
disability management programs (see for instance, the
modi®ed work literature review by Krause et al., 1998].
This outcome measure is inherently interesting because
reducing the duration of temporary disability bene®ts is
advantageous to employers and if associated with a decrease
in the days out of work, it is likely to be advantageous to
labor as well. However, the duration of temporary disability
indemnity does not count days missed during the waiting
period required in every state. More importantly, several
recent studies (all using workers' compensation administrative data supplemented with other sources) have shown
that unemployment subsequent to initial return to work or
after the end of temporary disability indemnity is common
among injured workers [Butler et al., 1995; Galizzi and
Boden, 1996; Biddle, 1998a; Krause et al., 1999; Reville,
1999].
A better way to estimate the consequences of injuries
for workers is to estimate the lost earnings over the years
after injuries using longitudinal data on earnings for injured
workers. This provides a better measure of consequences for
456
Reville et al.
injured workers if the injury leads to a higher probability of
work absence subsequent to the end of temporary disability
bene®ts. Since post-injury earnings data are not available in
workers' compensation data, these studies (referred to as
wage-loss studies) require linking claims data to another
administrative data source. The ®rst wage-loss studies are
Johnson et al. [1978] and Berkowitz and Burton [1987].
Both studies link claims data to social security earnings
records. The recent literature [Biddle, 1998a,b; Reville,
1999; Boden and Galizzi, 1999a,b; Reville et al., 2000;
Biddle et al., 2001; Reville and Schoeni, 2001] link claims
data to Unemployment Insurance (UI) earnings ®le, which
are available at the state level.
Two statistical approaches have been used in the recent
literature for estimating wage losses. Boden and Galizzi
[1999a] and Biddle [1998b] use a regression approach with
workers who suffer minor injuries as the control group. The
regression corrects for observable differences between the
controls and injured workers. Reville [1999] and Reville and
Schoeni [2001] adopt a matching approach to estimation
that is useful when the number of covariates available on the
data is small and the number of controls relative to injured
workers is large. The control group consists of up to ten
uninjured workers for each injured worker from the same
®rm as the injured worker (prior to injury) with the same
earnings. As an illustration of the advantages of linking to
data sources outside workers' compensation, this comparison group is possible by selecting additional workers from
the state UI earnings ®le.
When the data are available, the matching approach is
arguably more intuitive and imposes fewer parametric
assumptions than the regression approach. A problem with
the matching approach is the possibility that some injured
workers will not have controls; consequently, the resulting
sample will be unrepresentative. In addition, both matching
and regression approaches assume that selection is on
observed data alone. In other words, they assume that the
differences between injured workers and controls that may
affect the post-injury earnings patterns can be controlled for
using variables available in the data. This assumption may
be wrong if the control group is poorly chosen or if a critical
variable is missing. Since objections can be raised to any
non-experimental control group, comparisons with alternative control groups and the use of multiple methods are
helpful when possible.
Another possible source of bias occurs if injuries are
caused by or correlated with an unobservable event that
leads to wage loss. For example, if workers with grievances
against their employers are more likely to make a workers'
compensation claim and also more likely to quit or be ®red
whether or not a claim is made, then the effect of the injury
may be confounded by the effect of the grievance. One
solution to this problem is to include characteristics of the
employer, to the extent possible, in either the regression or
matching functions. For this, employers could be surveyed,
and the resulting data linked to the matched claims-wage
database.
Estimates of wage loss have typically counted the
earnings during periods of not working as zero. In this sense,
the observed loss in wages is not the same as the loss in
earnings capacity, and loss in earnings capacity may be
closer to the conception of policymakers as the intended
target for compensation. Methods of estimating wage
capacity for individuals out of work, the problem for which
this issue is an example, have occupied labor economists for
many years [Heckman, 1979], though have not been applied
in this context. One example of when the distinction
between wage loss and loss of wage capacity becomes
important is when interpreting differences in wage loss
across group, such as gender or age groups. For instance, if a
pension or social security is available, a workplace injury
may lead an older worker to retire when the same or a
greater injury would not have at an earlier age. This is an
example of greater wage loss without greater loss of
earnings capacity. At the same time, it is also possible that
older workers take longer to recover from workplace
injuries, which would imply greater loss of earnings
capacity at older ages. Policy or programs to assist older
workers would be different depending upon which explanation was more important in explaining higher losses observed with age.
Boden and Galizzi [1999b] and Biddle [1998b] ®nd that
the wage losses of men and women are equal on average, but
since women earn less than men, the proportional wage
losses are higher for women. One possible explanation for
this ®nding is that employers are more likely to discriminate
against women with injuries, offering them lower wages
than men with similar injuries. Another explanation is that
women have more alternative opportunities outside work
than men, and thus are more likely to stay out of the
workforce after an injury (for further discussion, see Boden
and Galizzi, 1999b]. Once again, sorting out the different
explanations may lead to different policy prescriptions.
The wage loss studies conducted thus far have all been
limited by the use of workers' compensation administration
data to claimed injuries. Indeed, the studies by Reville have
been limited to permanent disability claims, while the
Boden and Galizzi studies and the Biddle studies have also
examined less serious injuries. In future research, publicuse survey data such as the NLSY should be used for
examination of the earnings losses associated with unclaimed injuries as well.
Directions for Future Research
Economists since Adam Smith in The Wealth of Nations
have argued that the market must compensate workers
for occupational injury or fatality risks. Research on the
Economic Consequences of Workplace Injuries
existence and magnitude of these ``compensating wage
differentials'' has been far more extensive than the research
on wage loss and other injured worker outcomes.2 There
may be opportunities for cross-fertilization of these two
research areas. First, as improved estimates of wage loss
improve the estimates of the risks that workers face, detailed
estimates of average losses faced for injuries by occupation
could be calculated, and it may be possible to measure the
ex ante effect on worker's wages more accurately. Second, if
workers in risky jobs are receiving higher wages prior to
injury, and if an injury tends to cause workers to move to
less risky occupations, then measured wage losses may in
part re¯ect the loss of compensating wage differentials.
There have been no estimates of the quantitative importance
of this effect.
Another area that would be useful for future research is
estimation of income lost instead of wages lost. Evaluations
of the adequacy of workers' compensation bene®ts (the
purpose of every workers' compensation wage-loss study to
date) use the workers' compensation replacement rate as the
measure of adequacy. This measure is related to income lost,
but it ignores the availability of other income that may
follow from a workplace injury. For instance, there may be
other program income, such as disability insurance. It may
also be possible that a worker's spouse will increase his or
her labor force participation in response to the worker's
injury. This response would reduce lost income, and may
even increase lost wages (relative to unmarried workers),
depending upon the substitutability of a spouse's labor force
participation.
Ultimately, workplace injuries can affect other family
outcomes with unmeasured costs. It may be more dif®cult to
engage in household activities that are productive, perhaps
most signi®cantly child-raising. Spouses may increase labor
force participation or decrease it if the uninjured spouse
must provide care for the injured spouse. In general, a
fruitful avenue for further research would be to consider the
effect of injuries on families, taking into account the
interdependence of labor force decisions of husbands and
wives.
Analysis of lost income instead of wages, family
income, or bene®ts from alternative sources is dif®cult using
administrative data. It would require linking across multiple
data sources maintained by different administrative agencies. Linking spouses with administrative data is not likely
to be possible. Data on household production is certainly
unavailable. However, public use individual and household
surveys such as the PSID and the Health and Retirement
Survey (HRS) often contain information that can be used for
these kinds of analyses. They have been used for studies of
2
Among many economists, compensating wage differentials provide a preferred
method for estimating the costs of workplace injuries. Leigh et al. [2000]
provides a critique. See Viscusi [1993] and Dorman [1996] for reviews of the
compensating wage differential literature.
457
the employment and earnings consequences of disability
that do not distinguish between disabilities acquired on and
off work [Daly, 1994; Burkhauser and Daly, 1996; Charles,
1997; Charles and Stephens, 2000]. They have also been
used for studies of dislocation and downsizing [Ruhm,
1991; Haider and Stephens, 1999]. Stephens [1999] uses the
PSID to study the impact of both downsizing and disability
on consumption. Haider and Stephens [1999] use the HRS
to examine the impact of downsizing on retirement, health
insurance, and pensionsÐoutcomes that have not been
studied for workers' compensation.
Measuring the Consequences for
Employers
While data and methodological advances have led to a
large number of recent improvements in our estimation of
the consequences of injury for workers, no comparable
progress has been made in the estimation of the costs to
employers. By creating a safe working environment and
providing workers with equipment, employers may have
greater ability to control the number and severity of injuries
than workers have, and therefore, accurate estimation of the
full costs to employers is critical for education of the
employer community and for the design of policies intended
to improve safety.
Employers face considerable costs arising from workplace injury. One way to measure these costs is to measure
the total amount of workers' compensation bene®ts paid
(including medical, indemnity, and rehabilitation) in a given
year. The National Academy of Social Insurance [Mont
et al., 2000] estimates that employer costs estimated in this
manner was $41.7 billion in 1998. Alternatively, employer
costs can be estimated by summing payments to insurers,
state funds, and payments reported to regulators of selfinsured employers; this approach results for 1998 in an
estimate of $52.2 billion [Mont et al., 2000].
However, besides costs from workers' compensation,
workplace injuries impose many other costs upon employers. Bene®t payments or premium data do not capture lost
productivity from time out of work, overtime, retraining, or
other costs incurred by employers when injuries disrupt the
production process. Despite the potential size of these nonworkers' compensation employer costs, a lack of data has
caused the literature on employer costs from workplace
injuries to focus on the workers' compensation costs arising
from injuries [e.g., Krueger and Burton, 1990].3 A limited
description of the costs of workplace injuries to employers
3
Estimates of direct costs such as Mont et al. [2000] rely heavily on aggregate
data reported by employers to state Ratings Bureaus or to insurance data
collection organizations such as the NCCI or A.M. Best. In addition, data are
readily available on premiums paid by employers; these premiums include the
bene®ts paid to workers and also capture the insurers' administrative costs and
any insurer pro®ts. Data on self-insured employers are usually available only in
aggregate form from state regulators.
458
Reville et al.
TABLE I. Classification of Employer Costs
Direct costs
Ex ante costs
Ex post costs
Indirect costs
Workers'compensation insurance premiums (or their economic equivalent
for self-insured firms)
Injury-prevention programs
Costs of compliance with federal and state regulatory agencies
Payment of indemnity benefits (workers'compensation and other benefits)
Medical benefits for the injured worker (workers' compensation and other
health benefits)
Return-to-work programs
Costs of job accommodations
has resulted. This section describes a classi®cation scheme
for employer costs, summarizes studies that estimate the
direct costs of workplace injuries to employers, and
discusses some conceptual issues involved in estimating
indirect costs.
Classifying Employer Costs
A useful way to think about employer costs from
workplace injury is to divide the costs between ex-post and
ex-ante costs, those occurring before and after injury,
respectively. Estimates of employer costs using premiums
paid are estimates using ex ante costs, while estimates using
bene®ts paid are based on ex post costs.
Costs can be further classi®ed into direct and indirect
costs, which is a familiar distinction in the literature. Direct
costs show up on an employer's accounting balance sheet in
anticipation of workplace injury (if ex ante), or in response
to actual workplace injuries (if ex post). These are costs
incurred to prevent or compensate injuries. Indirect costs are
all other costs incurred by employers due to the existence
of workplace injuries, such as changes in wages paid to
all workers, and employment or training of replacement
workers.
Table I classi®es employer costs and provides examples
of these costs. It should not be construed as counting up all
the costs that employers face due to workplace injuries,
since several of the costs in the table double-count. For
example, workers' compensation premiums and bene®ts
measure the same cost paid by employers. While direct costs
are more likely to be included among employer costs, even
some of these, such as return-to-work and injury-prevention
programs are often not included in estimates of the costs of
workplace injuries.
The table lists the typical item in the direct ex ante cost
category: workers' compensation insurance premiums [used
to count costs in studies such as Krueger and Burton, 1990;
Mont et al., 2000]. It also lists other items such as the cost of
setting up injury-prevention programs and complying with
Compensating higher wages to workers for job risks
Redundant hiring to insure against workplace injury
Lost worker productivity
Training other workers to replace the injured worker
Decreased company morale
Overtime costs paid to other workers covering for theinjured worker
federal and state regulatory agencies. It also lists the typical
item in the direct ex post costs category: workers'
compensation medical and indemnity bene®ts [used to
count costs in Mont et al., 2000].4 However, it also lists
other indemnity programs and other medical bene®ts since
not all occupational injury costs are covered by workers'
compensation. In addition, other direct costs listed in the
table but not typically counted include the cost of job
accommodations and return-to-work programs.
The table lists as indirect ex ante costs the payment of
higher wages that may be associated with higher risk of
injury (compensating wage differentials discussed above). It
also lists the possibility of higher staf®ng in order to ®ll
positions vacant due to recovering injured workers. This is
in contrast to the indirect ex post costs listed including lost
productivity, training other workers, reduced morale, and
overtime costs.
The most comprehensive attempts to measure both
indirect and direct costs include Miller [1997] and Leigh
et al. [1997, 2000], which for instance include measures of
disruption costs to employers. Leigh et al. [2000] includes a
review of the literature on training costs, though these costs
have never speci®cally been measured in association with
workplace injuries. In general, data limitations require that
these studies rely on, for instance, aggregate training cost
measures and ad hoc assumptions to derive their estimates.
No studies that we are aware of have attempted a detailed
accounting of both indirect and direct costs at even a single
®rm, and certainly not at a large representative sample of
®rms. This is a glaring omission in the literature on the costs
of workplace injuries. It is most likely driven by a lack of
appropriate data.
4
Several studies compare medical costs for workers' compensation claims with
medical costs for similar injures not sustained in the workplace. For examples,
see Baker and Krueger [1995], Zaidman [1990], Johnson et al. [1993], Johnson
et al. [1996]. Studies in this literature tend to ®nd that medical costs are higher
in the workers' compensation sector, but none is able to fully account for
unobserved differences in the severity of injury between the two groups or, as
noted by Leigh and Ward [1997], unobserved differences in the costs of
treatment.
Economic Consequences of Workplace Injuries
Data Required: Linked Employee±
Employer Data
A key conceptual issue in examining employer's costs
from injury is that employers can trade off costs to minimize
total costs. For instance, they may discourage workers'
compensation claims in favor of claims against employerprovided health insurance if increases in utilization of health
insurance affect total costs by less. They may accept more
guarantees of employment after injury in exchange for
lower wages paid to the workers at risk of injury (an
example of a reduction in compensating wage differentials
in exchange for reduced risk).
Models for the type of data needed to address these
open questions about employer cost are rare. The most
promising approach is through the construction of linked
employee±employer databases, which combine extensive
information about a ®rm with administrative data or survey
data on the workers at the ®rm. Ideally, the most powerful
database of this type would include longitudinal data on
both the workers and the employers. For a large number of
studies using this type of database, see Haltiwanger et al.
[1999]. For a discussion (including a discussion of the
application of these data to occupational safety and health
issues), see Hamermesh [1999].
The simplest example of a database of this type for
occupational injury and illness research would be a
longitudinal database of workers' compensation claims for
a large sample of employers, combined with information
about the employers. However, this simple example would
not capture most of the costs described in Table I. A better
approach would be a longitudinal sample of injured
workers' wages and injuries, because if wage data are also
included, it could be possible to estimate the total labor costs
to the employer. Also using these data, it would be possible
to examine hiring or ®ring patterns. When multiple
employers are included with these data available for each,
they could provide a comprehensive view of the impact of
injury on employer personnel costs.
A similar approach could be used to construct a measure
of the impact of occupational injuries on employer medical
costs. The appropriate database would allow measurement of
the medical costs of unclaimed or ineligible injuries, and costshifting from workers' compensation to employer-provided
health insurance (and vice versa). Therefore, the linked
employer±employee database would be one that combined
longitudinal information on health claims and workers'
compensation medical claims for a sample of employers.
Linked employee±employer data for measuring the
costs of workplace injuries to employers may face greater
5
See the (slightly dated but still useful) reviews by Moore and Viscusi [1990]
and Krueger [1990]. In addition to papers described in this section, some other
signi®cant papers since these literature reviews include Ruser [1993] and Ruser
[1998].
459
con®dentiality concerns than the linked administrative data
that is used for estimating wage losses and other costs to
injured workers. This is because issues of con®dentiality of
individual medical records or wage records are compounded
with employer con®dentiality concerns. However, to the
extent that these concerns can be addressed, both employers
and employees will bene®t from the construction of these
databases, and the research and policy that they would
facilitate.
Insurance and Incentives
One potentially important indirect cost of workers' compensation arises because insurance bene®ts can change the
behavior of workers and employers. This situation is referred
to as moral hazard. For workers, moral hazard includes failing
to take safety precautions that would have been taken in the
absence of insurance, spending a longer period out of work
while receiving temporary disability bene®ts, or ®ling a
workers' compensation claim for non-work disability. Moral
hazard for employers includes the failure to provide safety
programs or to offer modi®ed work to injured employees
when the employer would have if facing full liability without
insurance. There is a large literature on moral hazard effects
of workers' compensation, though it has tended to ignore
moral hazard by employers in favor of focusing on the
behavior among employees.5 This literature has shown that
higher disability bene®ts increase the number of workers'
compensation claims. It has also shown that higher bene®ts
lead to greater time out of work for temporary disability
claimants. These results are frequently raised in political
debates surrounding proposed increases in statutory bene®ts
for injured workers because the implication is that costs to
employers will rise by more than the percentage increase in
statutory bene®ts.
Besides its limited scope, the primary shortcoming to
the moral hazard literature is that the positive correlation
between bene®ts and injury rates might arise for a number of
reasons, each with distinct normative implications. Greater
time out of work may mean more malingeringÐor more
time with suf®cient income to recover from the injury.
Increased claims may mean compensation for uninjured
workersÐor a greater fraction of legitimately injured
workers receiving bene®ts. Finally, since bene®t changes
are the outcome of a complicated political process that takes
injury rates into consideration, it is quite possible that higher
injury rates lead legislatures and regulators to raise bene®t
levels.6 To the extent that this relationship exists, the
positive correlation between bene®ts and injury rates can be
explained without recourse to insurance market imperfec-
6
Butler [1994] and Leigh [1985] suggest this possibility in their studies.
460
Reville et al.
tions.7 Some of the dif®culties interpreting the effects in the
moral hazard literature are due to data limitations. For
instance, no studies have examined the long-term consequences for injured workers (e.g., wage losses and
replacement rates or health status) associated with bene®t
changes, which would permit a better interpretation of the
impact of the increased time out of work that has been
estimated. Nor have any studies examined total employer
costs associated with changes in bene®ts, because improved
recovery by injured workers may simultaneously reduce
turnover and retraining costs and confound estimates. Such
a study would require information not available in unlinked
workers' compensation administrative databases. The CPS
data, which is not longitudinal, is also inadequate for this
purpose. No public use database exists with suf®cient
information on total employer costs.
CONCLUSION
While an extensive body of research exists on the
consequences of workplace injuries, many gaps in knowledge remain. However, increasingly, databases are available
that permit analysis of many of the open questions about
the impact of injuries on workers. A large literature has
developed recently using linked administrative databases to
explore the earnings and employment consequences of
workplace injuries and the extent of occupational injuries for
which workers' compensation is not claimed. We expect that
links to additional databases and further analysis using these
types of data will permit great strides in our understanding of
the consequences of occupational injury and illness for
workers.
Large, nationally representative, longitudinal databases
like the NLSY, HRS, and SIPP contain information about
injuries combined with extensive information about wages
and employment, as well as family income and participation
in public social insurance and income support programs.
However, these databases remain largely unused by
researchers in occupational safety and health. As researchers become aware of these databases and exploit the
information available in them, it will be possible to better
understand differences in the impact of occupational injury
and illness across demographic groups, the impact on
worker's families, and other outcomes.
We have noted the paucity of research on the costs to
employers of occupational injuries and illnesses outside
of workers' compensation costs. Given the role played
by employers in providing a safe and healthy workplace,
there is much to be gained from research into employer
costs. We describe the type of data that would facilitate
rigorous research in this area: linked employee±
employer databases, which are gaining favor among labor
economists.
Availability of data often drives the quality of research,
and high quality data are increasingly becoming available
for research in the economic consequences of occupational
injury and illness. We would like to see more public use
survey databases include the questions on occupational
injury and illness that are in the databases that we have
described. Recognizing that con®dentiality considerations
need to be addressed, we also would like to see more public
agencies (such as the Social Security Administration)
allowing their databases to be linked to other administrative
databases and made available for research. Finally, we
would like to see research funding agencies encouraging the
collection of employer data and the creation of linked
employee±employer databases with information on occupational injury and illness.
Appendix
Survey
Current Population Survey (CPS)
March Supplement
7
Description and Survey Highlights Relating to Disability
Monthly survey of approximately 50,000 households. A joint project of the Bureau of the Census and the BLS. Designed to
scientifically sample the civilian non-institutional population, the CPS inquires about labor force characteristics. The more
extensive March Supplement asks respondents whether they have received workers compensation payments, if any householdmemberhasa healthproblem,andifthatdisabilitylimitsworkability.Injuryidentifiedonly throughworkers'compensation.
Despite the conceptual limitations of this literature, two papers in this literature
merit particular attention due to data or methodological contributions. Krueger
[1990] constructs a nationally representative database of workers' compensation claimants using the CPS and estimates how the decision to claim workers'
compensation is affected by the bene®ts using variation across states in bene®t
generosity. Meyer et al. [1995] use a ``natural experiment approach'' involving
a maximum bene®t change and comparing workers affected by the change to
workers unaffected. While it is often politically impossible or expensive to
evaluate occupational safety and health programs using experimental methods,
there may be many opportunities for evaluation using linked administrative
data and the natural experiment method. For more on the natural experiment
approach, see, for example, Meyer [1994], Angrist et al. [1996], and Heckman
[1997] and Heckman [1998].
Economic Consequences of Workplace Injuries
Survey
Health and Retirement Study (HRS)
Waves1, 2, 3
Medical Expenditure Panel Survey
(MEPS)
National Health Interview Survey
(NHIS)
NHIS-D1994 Supplement; NHIS-D
1995-D Supplement
NHIS-Occupational Health
Supplement (1988)
National Longitudinal Survey of
Youth1979 (NLSY)
Panal Study of Income Dynamics
(PSID)
Survey of Income and Program
Participation (SIPP)
Survey of Program Dynamics (SPD)
461
Description and Survey Highlights Relating to Disability
A nationally representative longitudinal survey that focuses on retirement, aging, health insurance, and economic security.The
surveyoverviewincludesmonitoringofworkdisability asoneofitsobjectives.Queriesincludequestionsaskingrespondents
if health limits work ability and if the limitation resulted from a work-related injury, about workplace modifications and about
the physical demands of the job.Wave1includes questions about lifetime exposure to workplace hazards.
A nationally representative probability survey of non-institutionalized U.S. civilians on health-care issues. Collects data on
health care use, satisfaction, access, expenditures, and insurance. Asks if a medical condition was caused by an accident
or injury, and whether that injury occurred at work.
Part of the National Health Survey, which began in1957. A sample survey of the U.S. civilian non-institutionalized population.
Roughly 50,000 households are interviewed annually.The NHIS inquires about the incidence and extent of illness; disability
and chronic impairments; and health services received. The core NHIS asks whether an individual was injured seriously
during the previous three months, and whether that injury was work-related.
Supplementstothecore NHISsurvey thatcollectdisability data andorganizedtheminto a two-phase,detailedsurvey.Eligibility
for the second phase (titled the NHIS-D Followback Survey) is dependent upon the presence of a disability, as established in
the first phase.The NHIS-D asks if an injury was work-related; whether the individual had retired on disability; and whether
special accommodations would need to be made at the workplace so the person could work.
Cross-sectional supplement tothe NHIS designedtocollect national data on occupational health. Askswhether therespondent
filed a worker's compensation claim; how many days of work were missed; whether the respondent has back pain or hand
discomfort; and whether the individual had to alter the type of work performed as a result of the injury.
A national probability longitudinal sample of youth who were between the ages of14 and 21as of December 31,1978.Designed
to gather data on individuals' labor market experience and over-represents blacks, Hispanics and economically-disadvantagednon-blacks/non-Hispanics. Asksrespondentswhetherhealth is limitingthemfromworking; whether they had a workrelated injury; whether they filed a workers'compensation claim; whether they had to changethe type of workperformedas a
result; and whether the injury caused the respondent to lose wages or to be laid off.
An annuallongitudinalstudyofa nationallyrepresentativesample.Thesurveybegan in1968witha sample of5,000households
and has grown to a sample of approximately 8,700 households as of1995.Collects economic and demographic information,
such as income,employment,family structure, andresidence. Asks whetherrespondentsreceivedany incomefromworkers'
compensation, and asks whether a health or physical problem limits work ability.
Anational survey,consisting ofa continuousseries ofpanels,thatcollectsdata on income,laborparticipation, andeligibility and
participationin publicbenefitprograms,toestimate governmentprogramcosts andtomeasureprogrameffectiveness.Asks
whether respondents received any disability incomeöspecifically from workers' compensationöand asks whether a
health or physical problem limits work ability. Queries whether this health limitation is caused by an accident or injury on
the job, and asks whether the individual is able to work regularly at the same job they held before.
Anationallyrepresentativesampleofnon-institutionalizedcivilians.Interviewedapproximately30,000householdsthat werein
the1992 and1993 SIPP panels to determine economic status of individuals within and outside of the labor market. Collects
demographic data,labor market information, and data on respondents' workexperience,income and benefits. Asks whether
therespondents have received worker's compensation payments, and asks the respondents if they have trouble completing
everyday household activities, such as walking three city blocks or carrying a full bag of groceries.
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