Recent research by Wharton professor Brian Berkey discusses the impact of morality when making personal business decisions. The issues is not always crystal clear. Sometimes, personal gain may mean sacrificing form the greater good without an actually identifiable vicitm, making it tempting for individuals to take the path of personal gain.
Every decision is a tough one. But maybe we make them easier by sometimes only weighing personal benefits and costs and by choosing to ignore the victimless external costs that they may bring.
More on the research is available here.