Abstract
In the first part, I explore the start of daily smoking, which is often after the re-sorting of students between elementary and secondary education. I employ a novel identification strategy based on this re-sorting, in order to estimate peer effects in youth smoking.
The reflection problem is addressed by peers' pre-secondary-school smoking, which is not influenced by the current interaction. The self-selection is minimized by one's own presecondary school behavior and the pre-existing smoking prevalence among older schoolmates.
The empirical findings from the Czech Republic, where the prevalence of youth smoking has recently reached high levels, suggest that male youth smoking is affected by classmates, while female smoking is not. In the second part, I estimate the effect of opposite-gender peer drinking on individual risky sexual behavior among Czech youth.
The identification strategy relies on two main controls for individual and group-specific unobservables. First, younger schoolmates' sexual behavior is a control for school-specific attitudes toward sexual behavior.
Second, predetermined individual pre-secondary-school alcohol consumption is used to control for selfselection into schools of individuals with specific attitudes toward alcohol. As opposed to Waddell (2010), I find that female drinking affects the male propensity to have unprotected sex, while male drinking does not have such an effect on female behavior.
This finding corresponds to the fact that females have usually older sexual partners than males. In the last chapter, I investigate the impact of a change in the Czech early retirement scheme on the labor force participation of older male workers.
Using the difference-indifferences method I find that a reduction in early retirement benefits by 2-3% leads to approximately the same decrease in the probability of being inactive. The finding implies high elasticity of older male workers' participation rate.