global taxes, a new IMF working paper by Michael Kumhof and Romain Ranciere links inequality with financial crises. “The United States experienced two major economic crises over the past century—the Great Depression starting in 1929 and the Great Recession starting in 2007. Both were preceded by a sharp increase in income and wealth inequality, and by a similarly sharp increase in debt-to-income ratios among lower- and middle-income households. When those debt-to-income ratios started to be perceived as unsustainable, it became a trigger for the crisis. In this paper, we first document these facts, and then present a dynamic stochastic general equilibrium model in which a crisis driven by income inequality can arise endogenously. The crisis is the ultimate result, after a period of decades, of a shock to the relative bargaining powers over income of two groups of households, investors who account for 5% of the population, and whose bargaining power increases, and workers who account for 95% of the population. The model is kept as simple as possible in order to allow for a clear understanding of the mechanisms at work. The key mechanism is that investors use part of their increased income to purchase additional financial assets backed by loans to workers. By doing so, they allow workers to limit their drop in consumption following their loss of income, but the large and highly persistent rise of workers’ debt-to-income ratios generates financial fragility which eventually can lead to a financial crisis. Prior to the crisis, increased saving at the top and increased borrowing at the bottom results in consumption inequality increasing significantly less than income inequality. Saving and borrowing patterns of both groups create an increased need for financial services and intermediation. As a consequence the size of the financial sector, as measured by the ratio of banks’ liabilities to GDP, increases. The crisis is characterized by large-scale household debt defaults and an abrupt output contraction as in the 2007 U.S. financial crisis. Because crises are costly, redistribution policies that prevent excessive household indebtedness and reduce crisis-risk ex-ante can be more desirable from a macroeconomic stabilization point of view than ex-post policies such as bailouts or debt restructurings. To our knowledge, our framework is the first to provide an internally consistent mechanism linking the empirically observed rise in income inequality between high income households and poor to middle income households, the increase in household debt-to-income ratios among the latter group, and the risk of a financial crisis.” Conclusion (after lots of suitably impressive equations)? “restoration of poor and middle income households’ bargaining power can be very effective, leading to the prospect of a sustained reduction in leverage that should reduce the probability of a further crisis.” Dynamite. [h/t Matthew Lockwood] ]]>