Why Economists Should Conduct Field Experiments and 14 Tips for Pulling One Off

T he experimental approach has been a cornerstone of the scientifi c method for centuries. In one classic 1882 example, Louis Pasteur designated half of a group of 50 sheep as controls and vaccinated the other half. All animals then received a lethal dose of anthrax. Two days after inoculation, every one of the 25 control sheep were dead whereas the 25 vaccinated sheep were alive and well! However, many economists have long been pessimistic that an experimental approach could offer such vivid illustrations of cause and effect in their fi eld. For example, Samuelson and Nordhaus (1985) wrote in their introductory economics textbook a quarter-century ago: