This dissertation explores three questions in empirical public economics: we investigate the impact of social networks on labour market outcomes in the first essay; we explore the determinants of volunteering behaviour and estimate the effect of employment on volunteering in the second essay; and we examine the impact of political and fiscal decentralization on public provision in the third essay. In each case, we provide consistent estimates by utilizing an exogenous source of variation in key economic outcomes introduced by randomized policy experiments in the first two essays and by a natural experiment in the third essay. In the first essay, we find that among social networks, weak ties have a significant effect on labour market outcomes but strong ties do not have. In the second essay, we find that employment has a significant effect on volunteering behaviour, and that the effect varies in different contexts and depends on the precise channels through which the two are connected. In the final essay, we find that decentralization has a big effect on public provision. But we also find that decentralization affects different public goods differently, and that the key to its impact lies in the incentives facing politicians at the local level.