The Great Recession has brought with it a renewed interest in Hayek's business-cycle theory, which holds that loose monetary policy generates an unsustainable boom characterized by a lengthening of the capital structure. Hayek's theory has received robust criticism for decades, although the criticisms have varied in quality. Various empirical disconfirmations pose the most serious challenge. The small empirical literature on the subject generally confirms Hayek's predictions about variations in the capital structure, but has not persuasively linked the capital structure to (...) the business cycle. A better option, then, may be to abandon Hayek's business-cycle theory, preserve his capital theory, and graft it onto a Keynesian or monetarist understanding of the business cycle that is more consistent with modern macroeconomics. (shrink)