Corruption is generally defined as the misuse of public authority, and political corruption is here defined as corruption in which the political decision-makers are involved. In addition to a review of the various definitions of corruption a classification of the various forms of corruption (bribery, embezzlement, fraud and extortion), this paper presents two alternative theories on corruption ("extractive" and "redistributive") in order to illustrate the effects of corruption in various regime types. Furthermore, the paper presents some causes and effects of corruption, in particular in economic and political terms. Finally, various sources of anti-corruption initiatives and endowement are discussed (even when the effect of democratisation in curtailing corruption is not too strong according to the possible source of corruption).