This thesis comprises three essays. The first one focuses on the effect of a change in the labour market conditions induced by a trade shock on crime at the US local level. Using US Census data, I provide evidence that the increasing exposure to Chinese competitiveness has indirectly contributed to the change in the propensity to commit crime through a reduction of the expected labour market earnings. The second essay, which is co-authored with Vincenzo Bove and Roberto Nistic�, addresses the reasons why countries decide to transfer weapons only to specific recipients. We present novel empirical models of the arms trade and concentrate on the role of energy dependence, in particular of oil, in explaining the trade of weapons between countries. We find strong empirical support for the hypothesis that oil-dependent economies have incentives to provide security by selling or giving away arms to oil-rich countries and reduce their risk of political instability. Finally, the last essay, joint with Emanuele Ciani, has a specific focus on family economics. We provide evidence that parents who helped their adult children in the past are rewarded by higher chances of receiving informal care later in life. To this purpose we use Italian data containing retrospective information about help with housing received from parents at the time of marriage. We show a positive association with their current provision of informal care to them, which is robust to controlling for a large set of individual and family characteristics, and is confirmed by an IV regression using house prices as instrument. The results are in line with theories based on the presence of a third generation of grandchildren, such as those involving a demonstration effect or a family constitution
