The ethics of large businesses are extremely important for how a business is looked at by the general public. The corporate executives of companies have a responsibility to ensure that they are managing their business in accordance with the regulations set by the government. If a business doesn’t follow the social customs of its environment it will suffer consequences such as legal losses and bad headlines.
A good example of this would be the oil industry; in this article from the economist http://www.economist.com/node/1770490 the author discusses the careless and poor choices of business executives in major oil companies regarding their ethical practices. He brings up these points with a recurring theme that if a business has been behaving without conforming to social customs they will face major problems down the road.
While bribing foreign officials in the oil business is not unheard of, because these major companies are based in the USA they must follow the guidelines FCPA (a law which outlaws foreign bribery). Elected officials set the ethics these companies must follow and they are obligated to choose the most popular of all the choices. This makes companies responsible for abiding by the regulations they are given and accepting the punishments and setbacks they will face if they fail to follow the rules.