This interplay between theory and observation also occurs in the field of economics.An economist might live in a country experiencing rapid increases in prices and be moved by this observation to develop a theory of inflation.The the ory might assert that high inflation arises when the goverment prints too much money.(As you may recall,this was one of the Ten Principles of Economics in Chapter.1) To test this theory, The economist could collect and analyze data on prices and money from many different countries. If growth in the quantity of money were not at all related to the rate at wich prices are rising, the economist would start to doubt the validity of his theory of inflation. If money growth and inflation were strongly correlated in international data, as in fact they are, the economist would become more confident in his theory.