Abstract: Why do some countries have good institutions while others do not? Such is the question that we try to answer in this article. To do so, we empirically assess four different theories relating to the determinants of the quality of private property rights institutions: (a) The Economic Approach maintains that private property rights institutions are created when the benefits of their creation exceed their costs.(b) The Cultural Approach stipulates that countries have different institutions because of differences in the beliefs of their leaders about what would be good for the society.(c) The Historical Approach contends that cross country differences in the quality of private property rights institutions are the byproduct of historical accidents.(d) The Political Approach defends the premise that institutions are voluntarily chosen by the individuals who control political power. These individuals choose institutions aimed at maximizing their personal payoffs and not necessarily for the benefit of the whole society. The results of cross-sectional analysis over the period 1970-2005, with a sample of 142 countries (116 developing and 26 developed countries) show that the political approach is the most relevant. Indeed, the political approach is the most robust and it better fits private property rights institutions index. Independently of econometric specification and country sample, democracy positively affects private property rights institutions.