Despite its many errors, contemporary academic economics has improved considerably in recent decades, especially after the Keynesian detour of interventionism from the 1930s to the 1970s. There is a lagged influence between academic economics and public policy, but increasingly since the 1970s academic economists have recognized that free markets work, that “market failure” reflects poorly defined and ill-protected property rights, and that boom-bust cycles and sapped prosperity are consequences of bad public policies.