Psychological reasons why good people do bad things

The reason why is because when people who feel they are good do bad things, cognitive dissonance makes them ignore this behavior because they can't tolerate the inconsistency between their behavior and their beliefs.

Currently, as of february 2016, an american traveling in france would be by the exchange rate. the weakness of the euro and the strength of the us dollar means that items in france cost less to an american than they otherwise would. of course, if this trend reverses and the us dollar weakens and the euro strengthens, such as was happening in early 2008, an american traveling in france would have an adverse experience because items would cost relatively more.