Heterogeneous Effects by Disabling Condition

The divorce model is estimated using both disabled and nondisabled respondents. Initially, the sample of disabled respondents is restricted around the time of disability onset, from three years before to three years after. 10 The index references three t periods relative to the reference year: Years −2 and −1, Years 0 and 1, and Years 2 and 3. The nondisabled sample is then restricted to cover the range of ages and years spanned by the disabled sample—ages 27 to 57 and years 1980 to 1998—up to five calendar years after the reference year. Among the nondisabled, the sixth calendar year after the reference year corresponds with the year of the survey, which is not observed in retrospect. The estimates of the model are presented in Column 1 of Table 3. The baseline difference in divorce rates, in Year −3, is positive for both disability groups, but is statistically significant only for the work limited. As time elapses, the divorce rate among the work limited declines, reaching a level comparable to the nondisabled by Years 2 and 3. In contrast, the divorce rate among the work prevented increases then decreases, peaking to 1.78 percentage points in the year of and immediately after disability onset Year = 0,1. Although the estimate suggests that disability onset precipitates divorce, the coefficient is statistically insignificant at the 5 percent level. Statistical significance, however, appears to be a matter of statistical power. A less-parameterized alternative to the event-study model controls for disability-spe- cific trends in divorce, with deviations from trends in the years before and after disability onset. To properly estimate the trends in divorce, the sample of disabled respondents is expanded to include six years before to three years after disability onset. The estimates of this alternative model, which includes the same set of con- trols as the event-study model, are presented in Column 2 of Table 3. As shown, the onset of a work-preventing disability increases the rate of divorce by an estimated 1.77 percentage points, which is similar to the 1.78 percentage point increase from the event-study model. 11 Moreover, the estimate is statistically significant at the 5 percent level. The trends in divorce, measured by the interaction of disability status and “Year,” are negative, but statistically insignificant at the 5 percent level. The negative trend may reflect that, as marriages dissolve, average, unobserved marital quality increases, decreasing the divorce rate over time.

C. Heterogeneous Effects by Disabling Condition

The SIPP data contain information on the health conditions that limit work. One question, then, is whether the effect of disability on divorce depends on the nature of the disabling condition. The question is addressed using the event-study model of divorce. Conditions of the back and spine, the most commonly reported disability, are differentiated from all other health conditions. As before, the model also differ- entiates work-preventing from work-limiting disabilities. The index therefore cor- g 10. The analysis ends at Period 3 because the disabled sample declines as time since disability onset elapses, which occurs because the data are retrospective. In particular, the sample declines from 1,284 in Year 0 to 579 in Year 3 and 236 in Year 5. 11. As mentioned, the sample increases from Column 1 to 2 to properly estimate the trend in divorce. When the sample remains constant—more precisely, when the model in Column 2 is estimated using the sample in Column 1—the estimated increase in divorce among the work prevented at the time of onset Period = 0,1 is similar: 1.91 percentage points standard error: 0.78. Table 3 Linear Probability Model of Divorce Rate: Males Reference Ages 30 to 54 1 2 Model Event Study Time Trend Prevented 0.61 0.70 0.69 0.42 Year = −2,−1 0.74 0.40 0.87 0.64 Year = 0,1 1.78 1.77 0.95 0.77 Year = 2,3 − 0.27 0.92 Year − 0.17 0.10 Limited 1.3 0.66 0.64 0.34 Year = −2,−1 − 0.59 − 0.11 0.76 0.49 Year = 0,1 − 1.02 − 0.33 0.75 0.52 Year = 2,3 − 0.81 0.81 Year − 0.11 0.08 Observations 295,137 344,682 Data: Survey of Income and Program Participation, panels 1990 through 1996. Note: The unit of analysis is person and calendar year. The sample is conditioned on respondents who are married during the calendar year. The model includes controls for race, education, age, and marriage tenure and number. “Year” is relative to the reference year, which is the year disability onset for the disabled. Estimates are in percentage points. Standard errors, clustered by person, are in parentheses. , , and indicate significance at the 10, 5, and 1 percent level, respectively. responds to four groups: back and spine conditions that prevent work, back and spine conditions that limit work, all other conditions that prevent work, and all other conditions that limit work. Column 1 of Table 4 presents the estimates of the model. As shown, the only statistically significant increase in divorce at the time of disability onset is estimated for back and spine problems that prevent work. Divorce increases to 2.31 percentage points in the period before disability onset, and peaks to 3.89 percentage points in the period during and immediately after onset. No further disaggregation of health conditions yields statistically significant effects of disability on divorce. Thus, the association between work-preventing disabilities and divorce appear to be driven primarily by conditions related to the back or spine. Table 4 Linear Probability Model of Divorce Rate: Males Reference Ages 30 to 54 1 Medical Condition 2 Accident Back or Spine Other Accidental Not Accidental Prevented − 0.47 1.33 0.3 0.92 0.84 0.99 0.95 0.98 Year = −2,−1 2.31 − 0.3 1.33 0.17 1.3 1.2 1.25 1.2 Year = 0,1 3.89 0.4 2.28 1.3 1.4 1.3 1.4 1.3 Year = 2,3 − 1.04 0.15 0.31 − 0.8 0.85 1.4 1.4 1.2 Limited 1.48 1.18 1.59 1.02 1.0 0.81 0.97 0.85 Year = −2,−1 − 0.73 − 0.49 − 0.95 − 0.22 1.2 0.97 1.1 1.0 Year = 0,1 − 1.88 − 0.39 − 1.24 − 0.81 1.2 0.98 1.1 0.99 Year = 2,3 − 1.06 − 0.63 − 1.31 − 0.29 1.3 1.0 1.2 1.1 Observations 295,137 295,137 Data: Survey of Income and Program Participation, panels 1990 through 1996. Note: The unit of analysis is person and calendar year. The sample is conditioned on respondents who are married during the calendar year. The model includes controls for race, education, age, and marriage tenure and number. “Year” is relative to the reference year, which is the year disability onset for the disabled. Estimates are in percentage points. Standard errors, clustered by person, are in parentheses. , , and indicate significance at the 10, 5, and 1 percent level, respectively. The SIPP data also report whether the disabling condition was accidental. A simi- lar event-study model is estimated that differentiates between accidental and non- accidental disabilities and between work-preventing and work-limiting disabilities. The estimates are presented in Columns 2 of Table 4. The most notable estimates are for accidental disabilities that prevent work, reaching 2.28 percentage points in the year of and immediately following disability onset. Although the estimate is only significant at the 10 percent level, the result suggests that accidental disabilities have a greater effect on divorce.

D. Heterogeneous Effects by Age and Education