We discuss how leverage can be monitored for institutions, individuals, and assets. While traditionally the interest rate has been regarded as the important feature of a loan, we argue that leverage is sometimes even more important. Monitoring leverage provides information about how risk builds...

This is the graduation speech I gave on receiving an honorary doctorate at the University of Athens Economics and Business School. I talk about my Greek family, about how I got interested in economics, and then how in the 1990s I came to think about default, collateral, and leverage as the...

We show how the timing of financial innovation might have contributed to the mortgage bubble and then to the crash of 2007-2009. We show why tranching and leverage first raised asset prices and why CDS lowered them afterwards. This may seem puzzling, since it implies that creating a derivative...

A recent literature shows how an increase in volatility reduces leverage. However, in order to explain pro-cyclical leverage it assumes that bad news increases volatility, that is, it assumes an inverse relationship between first and second moments of asset returns. This paper suggests a reason...

I study the stability analysis of the solutions for the dynamical system of nonlinear asset flow differential equations (AFDEs) in three versions. I show that the previous two versions are not structurally stable mathematically because there are infinitely many critical points. It is important...

We study endogenous leverage in a general equilibrium model with incomplete markets. We prove that in any binary tree leverage emerges in equilibrium at the maximum level such that VaR=0, so there is no default in equilibrium, provided that agents get no utility from holding the collateral. When...

In our model, cross-currency basis, which captures the deviations from covered interest rate parity (CIP), reflects the relative value of the scarcer currency (US dollar) as collateral in funding constraints. Our empirical evidence shows that measures of dollar shortage derived from ECB tenders,...

We show that binomial economies with financial assets are an informative and tractable model to study endogenous leverage and collateral equilibrium: endogenous leverage can be highly volatile, but it is always easy to compute. The possibility of default can have a dramatic effect on...

We show that binomial economies with financial assets are an informative and tractable model to study endogenous leverage and collateral equilibrium: endogenous leverage can be highly volatile, but it is always easy to compute. The possibility of default can have a dramatic effect on...

Portfolio constraints often prevent financial derivatives from being synthetically created by primitive assets and thus, open a way for the 'redundant' assets to participate in expanding risk-sharing opportunities. They bring about peculiar portfolios, called 'link portfolios,' at an aggregate...