Financial innovations that change how promises are collateralized can affect investment, even in the absence of any change in fundamentals. In C-models, the ability to leverage an asset always generates over-investment compared to Arrow Debreu. The introduction of CDS always leads to...

In a production economy, in which agents have heterogeneous beliefs and a social planner has incomplete knowledge about which beliefs are correct, we introduce the concept of Incomplete Knowledge (IK) efficiency. IK-inefficient allocations can be improved upon without taking a stand on which...

This paper shows that credit default swaps (CDS) can affect the type of debt firms issue. Firms face a trade-off between investment scale and the cost of capital measured by the credit spread. Small-scale investment is safe, fully collateralized, but earns modest profits in all states....

We show how the timing of financial innovation might have contributed to the mortgage boom and then to the bust of 2007-2009. We study the effect of leverage, tranching, securitization and CDS on asset prices in a general equilibrium model with collateral. We show why tranching and leverage tend...

Coherent measures of risk defined by the axioms of monotonicity, subadditivity, positive homogeneity, and translation invariance are recent tools in risk management to assess the amount of risk agents are exposed to. If they also satisfy law invariance and comonotonic additivity, then we get a...

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...

We show that financial innovations that change the collateral capacity of assets in the economy can affect investment even in the absence of any shift in utilities, productivity, or asset payoffs. First we show that the ability to leverage an asset by selling non-contingent promises can generate...

We study a two-agent equilibrium model with two goods where we interpret the agents as countries. We analyze the effect of an endogenous habit specification where each country benchmarks its consumption decision against the decision of the other country. We show that endogenous habits can...

This paper delevops a tools to analyse the ordering of concordance of random vectors.

Evidence suggests that arbitragers exchange investment ideas. We analyze why and under what circumstances sharing occurs. Our model suggests that sharing ideas will lead to the following: more efficient asset prices, larger arbitrager profits, and correlated arbitrager returns. We predict that...