Dear Kezang, do you seek for information on corruption in general, or in health care (or any other branch)? As for health care, some years ago I did some study on this topic. Unfortunately, it was published only in Polish. As for corruption in general, you probably know the report by Transparency International: https://www.transparency.org/research/gcr/. Other organisations used to address this issue as well. For example OECD: http://www.oecd.org/corruption/.
Dear Kezang, rather than laboring searching specifically for the demand and supply side of corruption, you could presumably better look for the demand and supply side of accountability as a framework within which the issue of corruption features. You can find vast literature on it.
dear kezang, eventhough you´re probably interested more in formal economic and legal aspects, behavioral economics identifies on both sides, supply and demand, psychological perceptions that can foster corruption. when people hold a deeply rooted belief that they are personally not capable to achieve their ends otherwise or at similarly profitable conditions. this perception can be related not only to factual circumstance but also to a lack of self-efficacy for the ability necessary to achieve once goals. if you´re interested in these aspects too, i´ll gladly identify some papers for you. good luck with your research
There is an exchange of favors between the political and economic elites that is well captured by Patrick Chabal and Jean-Pascal Daloz in their work: Africa works: Disorder as Political Instrument. This is also reviewed by Kedmon N Hungwe. I Hope this will be useful for you.
I just published a paper on Cities that is entitled "Anti-corruption in Chinese Urban Planning: the Case of Adjusting FAR" (2017). I tried to set out a theoretic framework of corruption based on urban governance theory and then find some economic indicators for corruption. You may find it useful for your research.
I have sent the paper to you by email. However, some software (boxbe) appears to put it on wailist. So, please check your emails, especially those put on wait list.