Greed, the desire for power and the wish to advance oneself in society are primary reasons for corruption. Corruption typically flourishes in societies in which there is a high value placed on money, power and station in life. Its effects might include instability, distrust and unjustness.
Corruption also flourishes in areas in which resources are scarce, and the competition for them may lead some to become corrupt in either obtaining more of them or policing the distribution of them. Controlling corruption requires a balance between opportunity to obtain those things one desires with discretion in allocating them and accountability in how they are allocated. Many developing nations simply aren't stabilized enough to be able to form a central core that is organized enough to fend off corruption.
Corruption occurs in developed nations as well, particularly in ones where there is a strong correlation between financial worth, status and power. In some instances, corruption can have some short-term positive effects, particularly in those nations where too much government control is placed over resources. Here, corruption with the community still provides a system in which private citizens can gain those resources at a price and temporarily stabilizes the economy. Ultimately, though, corruption usually has negative effects on an economy through the funding of money into bribes and overpricing of goods and services, which puts a financial strain on too many people for too long. It also leads to tremendous distrust of public officials by citizens. It may also lead to an overall increase in crime.