For the past several years, Bruce Greenwald and I have been engaged in research on an alternative theory of the Depression—and an alternative analysis of what is ailing the economy today. This explanation sees the financial crisis of the 1930s as a consequence not so much of a financial implosion but of the economy’s underlying weakness. The breakdown of the banking system didn’t culminate until 1933, long after the Depression began and long after unemployment had started to soar. By 1931 unemployment was already around 16 percent, and it reached 23 percent in 1932. Shantytown “Hoovervilles” were springing up everywhere. The underlying cause was a structural change in the real economy: the widespread decline in agricultural prices and incomes, caused by what is ordinarily a “good thing”—greater productivity.

At the beginning of the Depression, more than a fifth of all Americans worked on farms. Between 1929 and 1932, these people saw their incomes cut by somewhere between one-third and two-thirds, compounding problems that farmers had faced for years. Agriculture had been a victim of its own success. In 1900, it took a large portion of the U.S. population to produce enough food for the country as a whole. Then came a revolution in agriculture that would gain pace throughout the century—better seeds, better fertilizer, better farming practices, along with widespread mechanization. Today, 2 percent of Americans produce more food than we can consume.

What this transition meant