The Macroeconomist as Scientist and Engineer

The subfield of macroeconomics was born, not as a science, but more as a type of engineering. The problem that gave birth to our field was the Great Depression. God put macroeconomists on earth not to propose and test elegant theories but to solve practical problems. This essay offers a brief history of macroeconomics, together with an evaluation of what we have learned. My premise is that the field has evolved through the efforts of two types of macroeconomists -- those who understand the field as a type of engineering and those who would like it to be more of a science. While the early macroeconomists were engineers trying to solve practical problems, the macroeconomists of the past several decades have been more interested in developing analytic tools and establishing theoretical principles. These tools and principles, however, have been slow to find their way into applications. As the field of macroeconomics has evolved, one recurrent theme has been the interaction -- sometimes productive and sometimes not -- between the scientists and the engineers. John Maynard Keynes (1931) famously opined, "If economists could manage to get themselves thought of as humble, competent people on a level with dentists, that would be splendid." As we look ahead, "humble" and "competent" remain ideals toward which macroeconomists can aspire.