If you are after some quantification you can find online the detailed ranking of the World Economic Forum (http://www.weforum.org/issues/competitiveness-0/gci2012-data-platform/) with country data on the perception of corruption
My favourite researcher of the question of trust, corruption, organisational behaviour, etc. in business, transition economies, competitve markets is Prof. Balázs Hámori. You can find some of his publications here https://www.researchgate.net/profile/Balazs_Hamori/publications/
or contact him through Corvinus University of Budapest, Dept. of Comparative Economics.
For your information, Singapore's government officials/civil servants are paid generously with a salary-plus-bonus package, which made these mandarins pretty greedy at work. Yet, SG's among the least corrupt states on earth (even cleaner than Switzerland http://cpi.transparency.org/cpi2013/results/ ). And of course, business there is spectacularly good. Hope this has not ruined your world.
I have studied this complex relationship in my recent book: Missing a Decent Living for Everyone: Success and Failure in 143 Countries. The book can be bought from www.morebooks.de or from www.amazon.com and it can also be read in ResearchGate. In principle, corruption (measured by CPI score) is better correlated to GNI (PPP) per capita than ease of doing business (ranked by The International Finance Corporation together with the World Bank). Corruption higlights the quality of public governance that again influence ease of doing business. Due to various feed-backs the relationships are quite complex.