Answer:
There have been three distinctive economic epochs in the hundred years following the First World War—the roaring twenties and the Great Depression, the golden age of capitalism and stagflation, and the great moderation and subsequent financial crisis of 2008.
The end of each of these epochs—the stock market crash of 1929, the decline in profits and investment in the late 1960s and early 1970s culminating in the oil shock of 1973, and the financial crisis of 2008, respectively—was a sign that institutions that had governed the economy to that point had failed.
The new institutions marking the golden age of capitalism—increased trade union strength and government spending on social insurance—addressed the aggregate demand problems highlighted by the Great Depression and were associated with rapid productivity growth, investment, and falling inequality.