Behind the Money Curtain: A Left Take on Taxes, Spending and Modern Monetary Theory Resource Type: Article Published: 2018 Taxes do not fund government spending.That's a core insight of Modern Monetary Theory (MMT) whose radical implications have not been understood very well by the left. Indeed, it's not well understood at all, and most people who have heard or read it somewhere breeze right past it, and fall back to the taxes-for-spending paradigm that is the sticky common wisdom of the left and right.