"Which theory of education argues that a high school diploma or college degree becomes a signaling device that matters more for predicting later attainment than what the student learned in school?

Donald  trump's  favorite color is orange. 

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.