A comparative study of corruption, inequality, and social trust.

摘要

My thesis explores two broad questions: (1) Does income inequality increase corruption? (2) Which explains cross-national variation in social trust better, fairness/unfairness such as corruption and inequality or homogeneity/heterogeneity such as ethnic diversity of a society?; Previous empirical studies have found the effect of inequality on corruption insignificant. I suspect that this is due to attenuation bias from large measurement error in inequality. I propose that inequality, in particular skewed income distributions, produce greater redistributive pressures, and hence greater motivation for corruption for the rich. Also, I argue that corruption and inequality, in particular skewness, generate sense of unfairness and erode social trust (generalized interpersonal trust). I conduct both large-N cross-national statistical analyses and small-N comparative historical case studies in order to test causal direction and identify causal mechanisms.; My quantitative cross-national study of 129 countries demonstrates that previous empirical studies failed to find the significance of inequality on corruption because of large measurement error in inequality. The use of averaged data, instead of single-year data, for inequality for a long period (1971-1996) in OLS regressions as well as the use of an instrumental variable (mature cohort size) for inequality in 2SLS produced significant and substantively large coefficients for inequality. Also, I find evidence that the effect of inequality on corruption is greater in democratic countries than in authoritarian regimes and that inequality adversely affects norms and perceptions about corruption.; My multilevel analysis using the World Values Surveys data shows that inequality, in particular skewness, and corruption have much stronger explanatory power than ethnic heterogeneity for the cross-national variations in social trust in a sample of 80 countries. Also, the evidence shows that the negative effect of inequality on trust is due to sense of unfairness rather than sense of dissimilarity.; In my comparative historical case study of South Korea, relative to Taiwan and the Philippines, I find that different levels of inequality, which were created by success and failure of land reform and differences in industrial policy, best explain the different levels of corruption and social trust among these countries.