Govert E. Bijwaard

Correcting for Selective Compliance in a Re-Employment Bonus Experiment

We propose a two-stage instrumental variable estimator that is consistent if there is selective compliance in the treatment group of a randomized experiment and the outcome variable is a censored duration. The estimator assumes full compliance in the control group. We use the estimator to reanalyze data from the Illinois re-employment bonus experiment.

The Impact of Labour Market Dynamics on the Return-Migration of Immigrants

Using administrative panel data on the entire population of new labor immigrants to the Netherlands, we estimate the effects of individual labor market spells on immigration durations using the timing-of-events method. The model allows for correlated unobserved heterogeneity across migration, unemployment, and employment processes. We find that unemployment spells increase return probabilities for all immigrant groups, while reemployment spells typically delay returns.

Estimated incident cost savings in shipping due to inspections

The effectiveness of safety inspections of ships has been analysed from various angles, but until now, relatively little attention has been given to translate risk reduction into incident cost savings. This paper provides a monetary quantification of the cost savings that can be attributed to port state control inspections and industry vetting inspections. The dataset consists of more than half a million ship arrivals between 2002 and 2007 and contains inspections of port state authorities in the USA and Australia and of three industry vetting regimes. The effect of inspections in reducing the risk of total loss accidents is estimated by means of duration models, in terms of the gained probability of survival. The monetary benefit of port state control inspections is estimated to range, on average, from about 70 to 190 thousand dollars, with median values ranging from about 20 to 45 thousand dollars. Industry inspections have even higher benefits, especially for tankers. The savings are in general higher for older and larger vessels, and also for vessels with undefined flag and unknown classification society. As inspection costs are relatively low in comparison to potential cost savings, the results underline the importance of determining ships with relatively high risk of total loss.

Prenatal Famine Exposure and Adult Mortality From Cancer, Cardiovascular Disease, and Other Causes Through Age 63 Years

Nutritional conditions in early life may affect adult health, but prior studies of mortality have been limited to small samples. We evaluated the relationship between pre-/perinatal famine exposure during the Dutch Hunger Winter of 1944-1945 and mortality through age 63 years among 41,096 men born in 1944-1947 and examined at age 18 years for universal military service in the Netherlands. Of these men, 22,952 had been born around the time of the Dutch famine in 6 affected cities; the remainder served as unexposed controls. Cox proportional hazards models were used to estimate hazard ratios for death from cancer, heart disease, other natural causes, and external causes. After 1,853,023 person-years of follow-up, we recorded 1,938 deaths from cancer, 1,040 from heart disease, 1,418 from other natural causes, and 523 from external causes. We found no increase in mortality from cancer or cardiovascular disease after prenatal famine exposure. However, there were increases in mortality from other natural causes (hazard ratio = 1.24, 95% confidence interval: 1.03, 1.49) and external causes (hazard ratio = 1.46, 95% confidence interval: 1.09, 1.97) after famine exposure in the first trimester of gestation. Further follow-up of the cohort is needed to provide more accurate risk estimates of mortality from specific causes of death after nutritional disturbances during gestation and very early life.

Return Migration of Foreign Students

Using administrative panel data, this paper presents a comprehensive empirical analysis of the return of recent foreign students in the Netherlands. We focus on how individual labour market changes and marriage formation influence their decision to leave. Our model allows for correlated unobserved heterogeneity across the migration, the labour market and the marriage formation processes. The large size of the data permits us to stratify the analysis by five groups based on the country of birth. The empirical analyses reveal that when students become unemployed they leave faster. The effect of finding a job on return is more ambiguous. For students from developed (including EU) countries it hardly affects their return, while students from less developed countries and Antilles/Surinam are more prone to leave after finding a job. Marriage in the Netherlands makes the students more prone to stay.

Modeling Purchases as Repeated Events

We put forward a statistical model for interpurchase times that incorporates all current and past information available for all purchases as time runs along the calendar time scale. It delivers forecasts for the number of purchases in the next period, as well as for the timing of subsequent and consecutive purchases. Purchase occasions are viewed as a counting process that counts the recurrent purchases for each house-hold as they evolve over time. We illustrate our model for yogurt purchases and highlight its managerial implications.

Gains in Life Expectancy Associated with Higher Education in Men

Background Many studies show large differences in life expectancy across the range of education, intelligence, and socio-economic status. As educational attainment, intelligence, and socio-economic status are highly interrelated, appropriate methods are required to disentangle their separate effects. The aim of this paper is to present a novel method to estimate gains in life expectancy specifically associated with increased education. Our analysis is based on a structural model in which education level, IQ at age 18 and mortality all depend on (latent) intelligence. The model allows for (selective) educational choices based on observed factors and on an unobserved factor capturing intelligence. Our estimates are based on information from health examinations of military conscripts born in 1944–1947 in The Netherlands and their vital status through age 66 (n = 39,798). Results Our empirical results show that men with higher education have lower mortality. Using structural models to account for education choice, the estimated gain in life expectancy for men moving up one educational level ranges from 0.3 to 2 years. The estimated gain in months alive over the observational period ranges from -1.2 to 5.7 months. The selection effect is positive and amounts to a gain of one to two months. Decomposition of the selection effect shows that the gain from selection on (latent) intelligence is larger than the gain from selection on observed factors and amounts to 1.0 to 1.7 additional months alive. Conclusion Our findings confirm the strong selection into education based on socio-economic status and intelligence. They also show significant higher life expectancy among individuals with higher education after the selectivity of education choice has been taken into account. Based on these estimates, it is plausible therefore that increases in education could lead to increases in life expectancy.

Life expectancy of artists in the Low Countries from the fifteenth to the twentieth century

We investigated the role that urbanization and plague may have played in changes in life expectancy amongst artists in the Low Countries who were born between 1450 and 1909. Artists can be considered to be representative of a middle-class population living mostly in urban areas. The dataset was constructed using biographical information collected by the Rijksbureau voor Kunsthistorische Documentatie in The Hague, the Netherlands. As early as the beginning of the sixteenth century, life expectancy at age 20 amongst the artists had reached 40 years. After a substantial decline in the late sixteenth and the early seventeenth centuries, when plague hit the region, life expectancy at age 20 began to rise again, and this upward trend accelerated after 1850. The life expectancy of female artists commonly exceeded that of males, and sculptors had better survival prospects than painters. In comparison with elite groups in the Low Countries and elsewhere in Europe, life expectancy amongst the artists was rather high.

Efficiency of Health Investment: Education or Intelligence?: EFFICIENCY OF HEALTH INVESTMENT: EDUCATION OR INTELLIGENCE?

Summary In this paper, we hypothesize that education is associated with a higher efficiency of health investment, yet that this efficiency advantage is solely driven by intelligence. We operationalize efficiency of health investment as the probability of dying conditional on a certain hospital diagnosis and estimate a multistate structural equation model with three states: (i) healthy, (ii) hospitalized, and (iii) death. We use data from a Dutch cohort born around 1940 that links intelligence tests at age 12 years to later‐life hospitalization and mortality records. The results indicate that intelligent individuals have a clear survival advantage for most hospital diagnoses, while the remaining disparities across education groups are small and not statistically significant.

Efficiency of Health Investment: Education or Intelligence?

In this paper we hypothesize that education is associated with a higher efficiency of health investment, yet that this efficiency advantage is solely driven by intelligence. We operationalize efficiency of health investment as the probability of dying conditional on a certain hospital diagnosis, and estimate a multistate structural equation model with three states: (i) healthy, (ii) ill (in hospital), and (iii) death. We use data from a Dutch cohort born around 1940 that links intelligence tests at age 12 to later-life hospitalization and mortality records. The results suggest that higher Intelligence induces the higher educated to be more efficient users of health investment - intelligent individuals have a clear survival advantage for most hospital diagnoses - yet for unanticipated health shocks and diseases that require complex treatments such as COPD, education still plays a role.