From the conclusion of the paper:
In the first, we explore anecdotal evidence suggesting that political rhetoric in developing countries is tilted to the left of the ideological spectrum. Thus, right-wing rhetoric is less extreme in poor countries than in rich countries while the rhetoric of left-wing parties appears more extreme in poor countries than in rich countries. Overall, this suggests that US-style, pro-capitalist political parties have electoral difficulties in the third world.
Our conjecture is that corruption plays a role in shaping ideologies. The paper provides empirical evidence that is consistent with the hypothesis that corruption moves the electorate to the left.
We discuss three types of evidence.
1. First, we argue that cross-country evidence showing that more regulation is correlated with more corruption is consistent with the idea that corruption reduces the appeal of capitalism.
2. Second, we present evidence on a link at the aggregate level between corruption and ideology within countries. We show that there is a negative correlation between a country’s aggregate level of corruption and how much to the right is the government in later years .
3. Third, we look at data on beliefs across individuals within countries. We show that people who think that corruption amongst public officials is widespread in the country tend to report themselves on the left of the political spectrum. (...) People who perceive there to be widespread corruption also tend to think that the government is doing too little to fight poverty or to think that the government should run firms (rather than owners and managers).
In other words, corruption begets socialism and socialism begets corruption. This is a complete vicious circle, which is almost impossible to escape for many countries. A very disturbing finding.