Her first question, whether free market economies can achieve full employment without government intervention, is a purely factual question that can be answered from history. For the first 150 years of the United States, there was no policy of federal intervention when the economy turned down.
No depression during all that time was as catastrophic as the Great Depression of the 1930s, when both the Federal Reserve System and Presidents Herbert Hoover and Franklin D. Roosevelt intervened in the economy on a massive and unprecedented scale.
Despite the myth that it was the stock market crash of 1929 that caused the double-digit unemployment of the 1930s, unemployment never reached double digits in any of the 12 months that followed the 1929 stock market crash.
Unemployment peaked at 9 percent in December 1929 and was back down to 6.3 percent by June 1930, when the first major federal intervention took place under Herbert Hoover. The unemployment decline then reversed, rising to hit double digits six months later. As Hoover and then FDR continued to intervene, double-digit unemployment persisted throughout the remainder of the 1930s.
Conversely, when President Warren G. Harding faced an annual unemployment rate of 11.7 percent in 1921, he did absolutely nothing, except for cutting government spending.
Keynesian economists would say that this was exactly the wrong thing to do. History, however, says that unemployment the following year went down to 6.7 percent -- and, in the year after that, 2.4 percent.
Under Calvin Coolidge, the ultimate in non-interventionist government, the annual unemployment rate got down to 1.8 percent. How does the track record of Keynesian intervention compare to that?