In 1943, Russian British Economist Abba Lerner wrote a paper entitled functional finance and the federal debt, in which he argued that governments should spend whatever is necessary for Full Employment. Lerner’s work received little notice in the years after its publication, and especially beginning in the 1980s when big government spending fell out of favor. More recently though, Australian Economist Bill Mitchell has revived and updated Lerner’s ideas into what is now called Modern Monetary Theory. Today, Progressive politicians, such as New York Congress representative Alexandria Ocasio-Cortez, are betting big on Modern Monetary Theory as a way to pay for programs like the green New Deal. More by necessity than by design, relief programs under the coronavirus pandemic are now putting Modern Monetary Theory to the test. Steven Pressman is a Professor of Economics at Colorado State University.