For example, the geography of Peru hasn't changed, but in the 15th century, it was the center of the wealthy Inca civilization. Conversely, the Native American cultures of North America were far less advanced than the Incas, but today the United States is the world's wealthiest nation. The reversal of fortunes, Acemoglu argues, is because of the different political and social Institut Ion-s colonial powers established, based on the conditions they found. In the sparsely populated American colonies, settlers created a relatively Open Society that allowed new players to participate in the economy and prosper. But in Peru, where the Spanish found a populous, UrbAn society, they exploited the conquered Incas, using them as slave labor and creating institutions that kept wealth in the hands of a few, ultimately resulting in an economy unable to renew itself and grow.