Across cultures, corruption is widely thought to be a destructive social phenomenon. Despite considerable efforts to understand its causes, there are still gaps in our understanding of how country corruption levels change over time. This study provides new insights by comparing the influence of societal values, wealth and political institutions on corruption for 59 countries from 1980 to 2008. Results suggest that self-expression societal values, wealth, and government size separate those countries that are less corrupt from those that are more corrupt. However, within countries, only increasing wealth is related to decreasing corruption, and this relationship varies across countries. This finding suggests that cross-sectional analyses provide an inadequate understanding of the dynamics of corruption over time; and that attempting to import institutions or impose values from low-corruption countries onto high-corruption countries is unlikely to be an effective short-term corruption-reduction strategy.