Hyman Minsky
Minsky proposed theories were about the normal life cycle of an economy. He linked financial market fragility with speculative investment bubbles in financial markets. Minsky claimed that in prosperous times, when companies make plenty of money, an irrational euphoria develops. Soon debts exceed what borrowers can pay off from their income, which produces a financial crisis. As a result, banks and lenders tighten credit, even to companies that can afford loans. Then the economy contracts.