In the recent NBER working paper, my co-author, Guillermo Ordoñez of the University of Pennsylvania, and I develop a model to examine the important role collateral plays in the economy. Where do safe assets come from? Empirical evidence suggests that the private sector creates more near riskless assets when the supply of government debt is low and reduces privately-created near riskless assets when the supply of government debt is high. Krishnamurthy and Vissing-Jorgensen (2012) show that the net supply of government debt is strongly negatively correlated with the net supply of private near-riskless debt.
The substitution between public and private safe debt is also shown by Krishnamurthy and Vissing-Jorgensen (2012) who document that changes in the supply of outstanding U.S. Treasuries have large effects on the yields of privately created assets. Gorton, Lewellen, and Metrick (2010) also find this relationship between government debt and privately produced substitutes. They document that the share of safe assets in the U.S. economy, including both U.S. Treasury debt and privately created near-riskless debt has remained constant as a percentage of all U.S. assets since 1952. Xie (2012) shows that the issuance of asset-backed securities tends to occur when the outstanding government debt is low and Sunderam (2012) documents the same phenomenon with respect to asset-backed commercial paper.
By “safe assets,” we mean government debt and privately created high quality debt, in particular, asset-backed securities. Such safe assets are used to collateralize repo, derivative positions, and are needed as collateral in clearing and settlement. See IMF (2012). Further, because they are ”information-insensitive” (in the nomenclature of Dang, Gorton, and Holmstrom (2012)), they are highly liquid and hence can store value without fear of capital losses in times of stress, a form of private money.