Persistencies in the Labour Market

Using longitudinal income-tax registers, we study how past labour market outcomes affect current labour market transition rates. We focus on hysteresis effects of the durations and incidence of previous spells out of work. We estimate flexible multi-state Mixed Proportional Hazard specifications for transition rates between employment, unemployment, and welfare/non-participation. Our main finding is that after longer periods of employment with high income, individuals' transition rates from unemployment to employment increase. Longer periods of non-employment generally decrease future transition rates to work, and sometimes also from work. The quantitative magnitude of persistency and hysteresis effects on inequality is modest.duration analysis, hysteresis, inequality, wages, unemployment, hazard rates, employment, income, work

Critical Periods During Childhood and Adolescence: A Study of Adult Height Among Immigrant Siblings

We identify the ages that constitute critical periods in children's development towards their adult health status. For this we use data on families migrating into Sweden from countries that are mostly poorer, with less healthy conditions. Long-run health is proxied by adult height. The relation between siblings' ages at migration and their heights after age 18 allows us to estimate the causal effect of conditions at a certain age on adult height. Moreover, we compare siblings born outside and within Sweden. We apply fixed-effect methods to a sample of about 9,000 brothers. We effectively exploit that for siblings the migration occurs simultaneously in calendar time but at different developmental stages (ages). We find important critical periods at ages 5/6 and 9. The effects are stronger in families migrating from poorer countries but weaker if the mother is well-educated.developmental origins, fetal programming, age, height retardation, adult health, parental education, migration, early-life conditions

Critical periods during childhood and adolescence: a study of adult height among immigrant siblings

We identify the ages that constitute critical periods in children’s development towards their adult health status. For this we use data on families migrating into Sweden from countries that are poorer, with less healthy conditions. Long-run health is proxied by adult height. The relation between siblings’ ages at migration and their heights after age 18 allows us to estimate the causal effect of conditions at certain ages on adult height. Moreover, we compare siblings born outside and within Sweden. We apply fixed-effect methods to a sample of about 9,000 brothers. We effectively exploit that for siblings the migration occurs simultaneously in calendar time but at different developmental stages (ages). We find some evidence for a critical period at age 9. The effects are stronger in families migrating from poorer countries but weaker if the mother is well-educated.Early-life conditions; migration; parental education; adult health; height retardation; age; fetal programming; developmental origins

Bounds on distance parameters of graphs.

Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2007.No abstract available

Persistencies in the labour market

Using longitudinal income-tax registers, we study how past labour market outcomes affect current labour market transition rates. We focus on hysteresis effects of the durations and incidence of previous spells out of work. We estimate flexible multi-state Mixed Proportional Hazard specifications for transition rates between employment, unemployment, and welfare/non-participation. Our main finding is that after longer periods of employment with high income, individuals' transition rates from unemployment to employment increase. Longer periods of non-employment generally decrease future transition rates to work, and sometimes also from work. The quantitative magnitude of persistency and hysteresis effects on inequality is modest