Leverage and deepening business cycle skewness

We document that the U.S. and other G7 economies have been characterized by an increasingly negative business cycle asymmetry over the last three decades. This finding can be explained by the concurrent increase in the financial leverage of households and firms. To support this view, we devise and estimate a dynamic general equilibrium model with collateralized borrowing and occasionally binding credit constraints. Improved access to credit increases the likelihood that financial constraints become non-binding in the face of expansionary shocks, allowing agents to freely substitute intertemporally. Contractionary shocks, on the other hand, are further amplified by drops in collateral values, since constraints remain binding. As a result, booms become progressively smoother and more prolonged than busts. Finally, in line with recent empirical evidence, financially-driven expansions lead to deeper contractions, as compared with equally-sized non-financial expansions

Leverage and deepening business cycle skewness

Documentamos que la economía de Estados Unidos se ha caracterizado por una asimetría del ciclo económico cada vez más negativa durante las últimas tres décadas. Este hallazgo puede explicarse por el aumento del apalancamiento financiero de hogares y empresas. Para mostrar esto, diseñamos y estimamos un modelo dinámico de equilibrio general con préstamos garantizados y restricciones de crédito ocasionalmente vinculantes. Un mayor apalancamiento aumenta la probabilidad de que las restricciones financieras se relajen ante perturbaciones expansivas, mientras que las perturbaciones contractivas se amplifican al hacerse estas restricciones más vinculantes. Como resultado, las expansiones se vuelven progresivamente más suaves y prolongadas que las recesiones. Por tanto, es posible conciliar una mayor asimetría negativa en el ciclo económico junto con la Gran Moderación en la volatilidad cíclica. Finalmente, de acuerdo con la evidencia empírica reciente, encontramos que las expansiones financieras llevan a contracciones más profundas que expansiones no financieras de igual tamañoWe document that the U.S. economy has been characterized by an increasingly negative business cycle asymmetry over the last three decades. This finding can be explained by the concurrent increase in the financial leverage of households and firms. To support this view, we devise and estimate a dynamic general equilibrium model with collateralized borrowing and occasionally binding credit constraints. Higher leverage increases the likelihood that constraints become slack in the face of expansionary shocks, while contractionary shocks are further amplified due to binding constraints. As a result, booms become progressively smoother and more prolonged than busts. We are therefore able to reconcile a more negatively skewed business cycle with the Great Moderation in cyclical volatility. Finally, in line with recent empirical evidence, financially-driven expansions lead to deeper contractions, as compared with equally-sized non-financial expansion

Reachability analysis for timed automata using max-plus algebra

International audienceWe show that max-plus polyhedra are usable as a data structure in reachability analysis of timed automata. Drawing inspiration from the extensive work that has been done on difference bound matrices, as well as previous work on max-plus polyhedra in other areas, we develop the algorithms needed to perform forward and backward reachability analysis using max-plus polyhedra. To show that the approach works in practice and theory alike, we have created a proof-of-concept implementation on top of the model checker opaal