AdamSmithee points to two recent papers that question measures of corruption derived from opinion surveys:

Two recent papers suggest that the noise-to-signal ratio in indicators built on perceptions of corruption is likely to be extremely high.  Ben Olken uses physical and financial audits to measure levels of corruption across villages in an Indonesian road project and then compares this measure to the levels of corruption perceived by villagers… [T]heir answers were far more strongly correlated with factors such as the level of ethnic diversity in the village than with actual levels of corruption.

Using a pretty nifty instrumental variable, James Feyrer & Bruce Sacerdote argue that colonialism improved the performance of island economies:

We have argued for an “islands as experiments” approach where random variation in the colonial experiences of islands can be used to think about the long run effects of colonial history on economic performance. The most interesting fact in our sample is a robust positive relationship between the years of European colonialism and current levels of income. While some of this relationship could be driven by smart selection of islands by
colonizers, we suspect that part of the relationship is causal. When we instrument for colonization and settlement using wind patterns, we obtain coefficients on years of colonization that are identical to our OLS results.

While the basic results suggest that longer European colonial exposure is good for the modern inhabitants of the islands in our sample, there are a few interesting caveats that we can introduce. First, there is a discernable pecking order amongst the colonizers. Years under US and Dutch colonial rule are significantly better than years under the
Spanish and Portuguese.

Second, later years of colonialism are associated with a much larger increase in modern GDP than years before 1700.