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 Nisticó, 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 countri...