The fiscal theory says that the price level is determined by the ratio of nominal debt to the present value of real primary surpluses. I analyze long-term debt and optimal policy in the fiscal theory. I find that the maturity structure of the debt matters. For example, it determines whether news...

I show that a determinate, finite price level can be achieved in an economy with no monetary frictions, and no commodity standard or other explicit redemption commitment. I make one small modification to a standard cash in advance model: I reopen the security market at the end of the day. With...

Exchange rates depreciate by the difference between the domestic and foreign marginal utility growths. Exchange rates vary a lot , as much as 10% per year. However, equity premia imply that marginal utility growths vary much more, by at least 50% per year. This means that marginal utility...

Are individuals effectively insured against idiosyncratic shocks to income or wealth by either formal or informal mechanisms? This paper shows that under perfect insurance, marginal utility should grow at the same rate for all consumers, and that the distribution of measured consumption growth...

I use the valuation equation of government debt to understand fiscal and monetary policy in and following the great recession of 2008-2009, to think about fiscal pressures on US inflation, and what sequence of events might surround such an inflation. I emphasize that a fiscal inflation can come...

I translate familiar concepts of discrete-time time-series to contnuous-time equivalent. I cover lag operators, ARMA models, the relation between levels and differences, integration and cointegration, and the Hansen-Sargent prediction formulas

Bennett McCallum (2009), applying Evans and Honkapohja's (2001) results, argues that "learnability" can save New-Keynesian models from their indeterminacies. He claims the unique bounded equilibrium is learnable, and the explosive equilibria are not. However, he assumes that agents can directly...

I address the controversy over whether the financial services industry is "too big." We should be asking whether the finance industry is functioning properly instead. The facts suggest that demand for financial services increased, perhaps temporarily, rather than suggesting a changing distortion...

Mean-variance portfolio theory can apply to the streams of payoffs such as dividends following an initial investment, in place of one-period returns. This description is especially useful when returns are not independent over time and investors have non-marketed income. Investors hedge their...

In standard solutions, the new-Keynesian model produces a deep recession with deflation in a liquidity trap. The model also makes unusual policy predictions: Useless government spending, technical regress, and capital destruction have large multipliers. These predictions become larger as prices...