Financial Instability and Income Inequality: why the connection Minsky-Piketty matters for Macroeconomics

In recent years the names of Minsky and Piketty gained increasing notoriety to researchers because the two authors investigated issues of nancial instability and income inequality, which represent both two unsolved macroeconomic problems of the new millennium, and evidence contradicting the long-run implications of mainstream macroeconomics. By combining these two names we set ourselves an ambitious goal, going beyond the technical aspects of the model presented in the paper. Indeed, not only we want to contribute directly to the debate meant at clarifying the controversial relationship between nancial instability and income inequality; we also aim at addressing a broader issue which is the explanation of the reasons why a theoretical revolution in macroeconomics has not yet occurred, and why nancial aspects still play a subordinate role to real factors in the explanation of growth and cycles. In this broader perspective Minsky and Piketty are assumed as extreme examples of the opposite poles of heterodoxy and orthodoxy. Both target and argumentative line of the contribution are quite unconventional, as usually nancial instability and income inequality, are treated as separate if not independent issues of inquiry; and methodological re ection is no longer a customary explicit part of technical papers. We discuss possible reasons why these two circumstances happen. The theoretical framework proposed in this paper builds on Ferri (2016), who presents a class of demandled models in a medium-run time horizon. This class of models is not conventional too, though it belongs to pedagogical models , we consider especially relevant tool for macroeconomics. Among the di erent speci cations investigated by the author, we select the nearest to possible comparison with Piketty (2014) and then we introduce corporate debt into the nancial account of rms. Because of the non-linearity of the model, we explore its dynamic properties with numerical simulations. Such simulations are also performed to assess the parameters enabling to support the Financial Instability Hypothesis. Aiming at deepening the comprehension of robustness properties, we also consider analytic results from a linearized version of the model. Obviously, the criticism addressed to Piketty with respect to the de nition and measurement of inequality can be extended to our model too, as we use the same expedient to check the evolution of inequality. This leads to emphasize the relevance of the issue of measurement as a critical one for future developments. Nevertheless, this does not impinge on the achievement of our purpose. Indeed, our analysis con rms the utility of pedagogical models. Furthermore, it underlines the need of a change of economic vision such that complexity comes as a substantial part of representation. In terms of future perspectives these considerations point out the need for macroeconomic epistemology to resume constructive dialectics: a mixture of plural narratives and foundations for new visions of economic policy. Those just proposed at the end of the paper di er from orthodox ones as they call for nancial regulation, they underline qualitative aspects and heterogeneity; but such embryonal policy suggestions stem from the overall perspective described in the paper, a perspective rooted into Ferri's notion of medium-run, and quali ed by Minsky through an eclectic approach leading to networks of balance-sheets: two ways highly overlapping though not totally equivalent to represent the reality of and endogenously unstable capitalism lying at the edge of chaos.