In the 1970s a series of developments occurred that shook neo-Keynesian theory. The developed world suffered from slow economic growth and high inflation at the same time (stagflation). Also, the work of monetarists like Milton Friedman cast doubt on neo-Keynesian theories. The result was a series of new ideas to bring tools to Keynesian analysis that would be capable of explaining the economic events of the 1970s. The next great wave of Keynesian thinking began with the attempt to give Keynesian macroeconomic reasoning a microeconomic basis. The new Keynesians helped create a "new neo-classical synthesis" that currently forms the mainstream of macroeconomic theory. Following the emergence of the new Keynesian school, neo-Keynesians have sometimes been referred to as Old-Keynesians.