美国公共债务与安全资产市场势力

The US government is the dominant supplier of global safe assets and faces a downward sloping demand for its debt. In this paper, we ask if the US exercises its market power when issuing debt, and we study its macroeconomic consequences. We develop a model of the global economy in which US public debt generates a nonpecuniary value for its holders, analyze the equilibrium in which the US government is themonopoly provider of this safe asset, and contrast this casewith the one inwhich the US government acts as a price taker. We use variation in estimated demand elasticities for US debt during highand low-volatility regimes to empirically distinguish between these two models and find that the data reject the price-taking behavior in favor of the monopoly one. We then quantify the distortions due to market power and find that it generates a significant underprovision of safe assets, a sizable markup in the convenience yield, and large welfare benefits for the US to the detriment of the rest of the world. Finally, we study the implications of increasing competition in safe assets from other sovereigns and private institutions. ∗Aprevious draft of this paper circulated under the title “TheMacroeconomic Implications of USMarket Power in Safe Assets.” We thank Manuel Amador, Andy Atkeson, Anmol Bhandari, V. V. Chari, Chris Conlon, Marco Duarte, Simon Gilchrist, Oleg Itskhoki, Rohan Kekre, Arvind Krishnamurthy, Zhengyang Jiang, Ricardo Lagos, Hyunju Lee, Hanno Lustig, Matteo Maggiori, Lorenzo Magnolfi, Dmitry Mukhin, Chris Sullivan, and Venky Venkateswaran, as well as numerous seminar and conference participants, for helpful comments and suggestions. We also thank Duong Dang for superb research assistance.