We study optimal public portfolios in a class of macro-finance models that includes widely used specifications of households’ risk and liquidity preferences, market structures for financial assets, and trading frictions. An optimal portfolio hedges fluctuations in interest rates, primary surpluses, and income inequalities. We express an optimal portfolio in terms of statistics that are functions only of macro and financial market data. An application to US data shows that hedging interest rate risk plays a dominant role in shaping an optimal maturity structure of US government debt.

The dynamics of a linear (or linearized) dynamic stochastic economic model can be expressed in terms of matrices (A, B, C, D) that define a state space system for a vector of observables. An associated state space system (A, ^ B,C, ^D) determines a vector autoregression for those same observables. We present a simple condition for checking when these two state space systems match up and when they do not when there are equal numbers of economic and VAR shocks. We illustrate our condition with a permanent income example.

From a new data set, we infer time series of term structures of yields on U.S. federal bonds during the gold standard era from 1791–1933 and use our estimates to reassess historical narratives about how the United States expanded its fiscal capacity. We show that U.S. debt carried a default risk premium until the end of the nineteenth century, when it started being priced as an alternative safe asset to U.K. debt. During the Civil War, investors expected the United States to return to a gold standard so the federal government was able to borrow without facing denomination risk. After the introduction of the National Banking System, the slope of the yield curve switched from down to up and the premium on U.S. debt with maturity less than one year disappeared.