The Columbian Exchange refers to the exchange of diseases, ideas, food crops, and populations between the New World and the Old World following the voyage to the Americas by Christopher Columbus in 1492.
The Old World—by which we mean not just Europe, but the entire Eastern Hemisphere—gained from the Columbian Exchange in a number of ways. Discov- eries of new supplies of metals are perhaps the best known. But the Old World also gained new staple crops, such as potatoes, sweet potatoes, maize, and cassava. Less calorie-intensive foods, such as tomatoes, chili peppers, cacao, peanuts, and pineap- ples were also introduced, and are now culinary centerpieces in many Old World countries, namely Italy, Greece, and other Mediterranean countries (tomatoes), India and Korea (chili peppers), Hungary (paprika, made from chili peppers), and Malaysia and Thailand (chili peppers, peanuts, and pineapples). Tobacco, another New World crop, was so universally adopted that it came to be used as a substitute for currency in many parts of the world. The exchange also drastically increased the availability of many Old World crops, such as sugar and coffee, which were particularly well-suited for the soils of the New World.
The exchange not only brought gains, but also losses. European contact enabled the transmission of diseases to previously isolated communities, which
■ Nathan Nunn is an Assistant Professor of Economics, Harvard University, Cambridge, Massachusetts. During the 2009–2010 academic year, he was the Trione Visiting Professor of Economics at Stanford University, Stanford, California. Nancy Qian is an Assistant Professor of Economics, Yale University, New Haven, Connecticut. Both authors are also Faculty Research Fellows, National Bureau of Economic Research (NBER), Cambridge, Massachu- setts, and Affifiliates, Bureau for Research and Economic Analysis of Development