One of the top reasons for allowing corruption by business people, other than getting ahead, is to incentivise speediness in business process.
http://www.straitstimes.com/opinion/fight-against-corruption-singapores-experience
The story is told of a businessman who visited Singapore from an Asian country used to different operating norms. He left puzzled and disturbed that he could not discover the going rate for bribes to officers at different levels of government. He concluded wrongly that the prices must be very high.
Singapore has achieved some success eradicating corruption, but we are under no illusions that we have permanently and completely solved the problem. Corruption is driven by human nature and greed. However strict the rules and tight the system, some individuals will sometimes still be tempted to transgress. When they do, we make sure they are caught and severely dealt with. Two years ago, we charged an assistant director from the CPIB itself with misappropriating $1.7 million.
http://blog.moneysmart.sg/opinion/singapores-top-5-corruption-cases-so-far/
http://www.tradingeconomics.com/singapore/corruption-rank
Singapore is the 8 least corrupt nation out of 175 countries, according to the 2015 Corruption Perceptions Index reported by Transparency International. Corruption Rank in Singapore averaged 5.24 from 1995 until 2015, reaching an all time high of 9 in 1997 and a record low of 1 in 2010. Corruption Rank in Singapore is reported by the Transparency International.