Jan Ondrich

The Duration of Post-injury Absences from Work

The authors use three duration models to estimate the effects of disability benefits on the hazard of returning to work and on the expected duration of work absences. The results show that disincentives exist even when disability benefits are not conditioned on the recipient remaining out of work. In addition, blacks and women are found to be absent longer than white men. Durations of work absences are also influenced by available wages, the type and severity of injury, the physical demands of the jobs for which the worker is qualified, and the willingness of employers to help the worker return to work. Copyright 1990 by MIT Press.

The Liberalization of Maternity Leave Policy and the Return to Work after Childbirth in Germany

German federal law has increased the potential duration of maternity leave five times since 1985. A theoretical model demonstrates that the cumulative return probability at potential duration cannot decline unless the mothers employment conditions or career expectations change. We estimate return to work hazards from the German Socio-Economic Panel for women bearing children in the period 1984–1991 and predict cumulative return probabilities for first-time mothers and mothers with a previous birth. The pattern of cumulative return probabilities as potential duration increases is consistent with the hypothesis that employment conditions or career expectations frequently change for mothers taking longer leaves.

Efficiency measurement in the stochastic frontier model

Abstract Deterministic models of technical efficiency assume that all deviations from the production frontier are due to inefficiency. Critics argue that no allowance is made for measurement error and other statistical noise so that the resulting efficiency measure will be contaminated. The stochastic frontier model is an alternative that allows both inefficiency and measurement error. Advocates argue that the stochastic frontier models should be used despite other potential limitations because of the superior conceptual treatment of noise. As will be demonstrated in this paper, however, the assumed shape of the error distributions is used to identify a key production function parameter. Therefore, the stochastic frontier models, like the deterministic models, cannot produce absolute measures of efficiency. Moreover, we show that rankings for firm-specific inefficiency estimates produced by traditional stochastic frontier models do not change from the rankings of the composed errors. As a result, the performance of the deterministic models is qualitatively similar to that of the stochastic frontier models.

Do Real Estate Brokers Choose to Discriminate? Evidence from the 1989 Housing Discrimination Study

Discrimination is systematic unfavorable treatment based solely on group membership. This study focuses on racial and ethnic discrimination in qualitative actions by real estate brokers, such as showing an advertised house, based on 2000 audits conducted in 1989. Each audit consists of a visit to a broker by a white person and a black or Hispanic person with equal qualifications. The audit data are used to measure the incidence of discrimination and to test hypotheses about its causes. The results reveal widespread discrimination and indicate that brokers discriminate based on personal prejudice and the prejudice of white clients.

Do Community-Based, Long-Term-Care Services Reduce Nursing Home Use? A Transition Probability Analysis

This study offers logit estimates of the probability of transition from the community to a nursing home based upon data from the National Long-Term-Care Demonstration. It is found that nurses deter entry by those using a wheelchair while home-health aides deter entry for those with cognitive impairments. Personal-care aides and housekeepers reduce admission risk for those with severe functional disabilities. These findings suggest that appropriate targeting of community-based services would improve the degree to which they offset nursing home expenditures.

The determinants of teacher attrition in upstate New York

Policy makers and scholars have long been interested in teacher attrition, particularly in poor, urban schools. We investigate the determinants of teacher attrition in five large metropolitan areas in upstate New York. We focus on a teachers decision to leave a school district or to leave teaching using the Prentice-Gloeckler-Meyer technique for proportional hazards with unobserved heterogeneity. We find that teachers in districts with higher salaries relative to nonteaching salaries in the same county are less likely to leave teaching and that a teacher is less likely to change districts when he or she teaches in a district near the top of the teacher salary distribution in that county. We also find, however, that the impact of salary on the probability of leaving teaching is small and that very large salary increases would be required to offset the impact of concentrated student disadvantage on the attrition of female teachers.

A Limited Joint-Choice Model for Discrete and Continuous Housing Characteristics

A simultaneous discrete and continuous random utility model for housing demand is presented. Household utility depends on three characteristics of hou sing: a discrete number of bedrooms and continuous measures of hous-i ng quality and distance to the central business district. Empirical r esults for a sample of renter households from San Francisco are compa red for a univariate structure in which each choice variable has its own utility or disutility function, a simultaneous structure assuming a discrete-continuous analog of the independence of irrelevant alter natives, and one for which this assumption is relaxed. The results in dicate that the third structure is most appropriate. Copyright 1988 by MIT Press.

Care of Children in a Low Fertility Setting: Transitions Between Home and Market Care for Pre-school Children in Germany

Because it may affect a nations fertility, child care policy is an important policy instrument for low-fertility countries. Designing an effective policy requires an understanding of the determinants of demand for child care. This study uses a descriptive statistical approach to analyze the dynamics of demand for child care for pre-school children in Germany. Age-specific and duration-specific hazard rates for leaving home care and for leaving market care are calculated for various risk groups. Hazard rate differences across risk groups indicate the presence of important factors affecting transitions. We examine household characteristics, the mothers employment status, and regional supply. We find that households with working mothers and fewer pre-school children have greater demand for market care. There also appears to be excess demand for market care. The hazard rates of subsequent children do not differ significantly from those of the first child.

Disability Trajectories at the End of Life: A “Countdown” Model

OBJECTIVES Studies of late-life disablement typically address the role of advancing age as a factor in developing disability, and in some cases have pointed out the importance of time to death (TTD) in understanding changes in functioning. However, few studies have addressed both factors simultaneously, and none have dealt satisfactorily with the problem of missing data on TTD in panel studies. METHODS We fit latent-class trajectory models of disablement using data from the Health and Retirement Study. Among survivors (~20% of the sample), TTD is unknown, producing a missing-data problem. We use an auxiliary regression equation to impute TTD and employ multiple imputation techniques to obtain final parameter estimates and standard errors. RESULTS Our best-fitting model has 3 latent classes. In all 3 classes, the probability of having a disability increases with nearness to death; however, in only 2 of the 3 classes is age associated with disability. We find gender, race, and educational differences in class-membership probabilities. DISCUSSION The model reveals a complex pattern of age- and time-dependent heterogeneity in late-life disablement. The techniques developed here could be applied to other phenomena known to depend on TTD, such as cognitive change, weight loss, and health care spending.

Multiple spells in the Prentice-Gloeckler-Meyer likelihood with unobserved heterogeneity

Abstract Based on previous work by Prentice and Gloeckler (Prentice, R.L., Gloeckler, L.A., 1978. Regression analysis of grouped survival data with application to breast cancer data. Biometrics 34, 57–67), Meyer shows how to estimate, for single-spell data, a proportional hazard with time-varying covariates and unobserved heterogeneity for which the effect of time on the hazard rate is specified non-parametrically. With multiple-spell data, the number of terms in each likelihood contribution grows geometrically with the number of spells. We present a systematic method of ordering the terms in the multiple-spell case and using the binary representation of the order number to construct the likelihood contributions.