You can call an economist a Keynesian if she follows the ideas of the early twentieth century British economist John Maynard Keynes — and the ideas themselves are also Keynesian. It's not uncommon to hear political pundits criticizing politicians as Keynesian, although the theories themselves simply favor a mix of a private sector economy with government intervention when necessary. One Keynesian idea is that unemployment results from problems with the economic system itself, rather than people's unwillingness to work.