Research
Financial Markets and the Real Economy
In Rajnish Mehra, Ed. Handbook of the Equity Premium Elsevier 2007, 237-325. Everything you wanted to know, about the equity premium, consumption-based models, investment-based models, general equilibrium in asset pricing, labor income and idiosyncratic risk. Click the title for more information.
In Rajnish Mehra, Ed. Handbook of the Equity Premium Elsevier 2007, 237-325. Everything you wanted to know, but didn’t have time to read, about equity premium, consumption-based models, investment-based models, general equilibrium in asset pricing, labor income and idiosyncratic risk.
This article appeared four times, getting better each time. (Why waste a good article by only publishing it once?) The link above is the last and the best. The previous versions were NBER Working paper 11193, Financial Markets and the Real Economy Volume 18 of the International Library of Critical Writings in Financial Economics, John H. Cochrane Ed., London: Edward Elgar. March 2006, and in Foundations and Trends in Finance 1, 1-101, 2005.
A Brief Parable of Overdifferencing
This is a short note, showing how money demand estimation works very well in levels or long (4 year) differences, but not when you first-difference the data. It shows why we often want to run OLS with corrected standard errors rather than GLS or ML, and it cautions against the massive differencing, fixed effects and controls used in micro data. It's from a PhD class, but I thought the reminder worth a little standalone note.
This is a short note, showing how money demand estimation works very well in levels or long (4 year) differences, but not when you first-difference the data. It shows why we often want to run OLS with corrected standard errors rather than GLS or ML, and it cautions against the massive differencing, fixed effects and controls used in micro data. It's from a PhD class, but I thought the reminder worth a little standalone note.
Continuous-time linear models
Foundations and Trends in Finance 6 (2011), 165-219. How to do ARMA models, opreator tricks, and Hansen-Sargent prediction formulas in continuous time.
Foundations and Trends in Finance 6 (2011), 165-219. How to do ARMA models, opreator tricks, and Hansen-Sargent prediction formulas in continuous time.
Time series for macroeconomics and Finance
Jan 2005 Lecture notes for PhD time series course. This revision finally includes the figures!
Jan 2005 Lecture notes for PhD time series course. This revision finally includes the figures!
Permanent and Transitory Components of GNP and Stock Prices
Quarterly Journal of Economics CIX (February 1994) 241-266. This is my favorite solution to the permanent/transitory decomposition issue for GNP and stock prices. I use bivariate autoregressions of consumption and GNP, and of dividends and stock prices. Consumption and dividend growth are unpredictable, so act as stochastic trends for GNP and stock prices. A movement in stock prices with no current change in dividends is completely transitory, so can be labeled an “expected return” shock. A movement in stock prices with a change in dividends is permanent and so is a “permanent earnings” shock. Note the QJE switched Figure II and III.
Quarterly Journal of Economics CIX (February 1994) 241-266. This is my favorite solution to the permanent/transitory decomposition issue for GNP and stock prices. I use bivariate autoregressions of consumption and GNP, and of dividends and stock prices. Consumption and dividend growth are unpredictable, so act as stochastic trends for GNP and stock prices. A movement in stock prices with no current change in dividends is completely transitory, so can be labeled an “expected return” shock. A movement in stock prices with a change in dividends is permanent and so is a “permanent earnings” shock. Note the QJE switched Figure II and III.
A Critique of The Application of Unit Root Tests
Journal of Economic Dynamics and Control 15 (April 1991) 275-284. Running a battery of unit root/cointegration tests and then imposing the answers on subsequent analysis is a bad idea. Alas, there is no substitute for plotting the data and thinking about what makes sense.
Journal of Economic Dynamics and Control 15 (April 1991) 275-284. Running a battery of unit root/cointegration tests and then imposing the answers on subsequent analysis is a bad idea. Alas, there is no substitute for plotting the data and thinking about what makes sense.
How Big is the Random Walk in GNP?
Journal of Political Economy 96 (October 1988) 893-920. Short-order ARMA models suggest that GNP looks a lot like a random walk. But short-order ARMA models are fit to match one-step ahead forecasts, and can do a poor job of capturing long-term forecastability. I used a variance-ratio statistic (variance of long-term differences / variance of one-year differences) to show that there is a lot of mean-reversion in GNP that short-order ARMA models miss. I think the subsequent “permanent and transitory components” answers the substantive question better, but the warning about using long-term implications of short-term models remains worthwhile today.
Journal of Political Economy 96 (October 1988) 893-920. Short-order ARMA models suggest that GNP looks a lot like a random walk. But short-order ARMA models are fit to match one-step ahead forecasts, and can do a poor job of capturing long-term forecastability. I used a variance-ratio statistic (variance of long-term differences / variance of one-year differences) to show that there is a lot of mean-reversion in GNP that short-order ARMA models miss. I think the subsequent “permanent and transitory components” answers the substantive question better, but the warning about using long-term implications of short-term models remains worthwhile today.
Multivariate Estimates of the Permanent Components in GNP and Stock Prices
Journal of Economic Dynamics and Control, 12 (June/July 1988) 255-296. (With Argia M. Sbordone). This paper sits halfway between the “random walk in GNP” JPE and “permanent and transitory components” QJE. The “random walk” is univariate. Here, we realized that consumption could tell you a lot about the permanent component of GNP. Here, we use that insight in spectral and variance-ratio calculations. The answers are the same as in “permanent and transitory components”, but I now prefer the simpler VAR treatment in that paper. When GNP or stock prices are cointegrated with a random walk the subtle long-horizon and “nonparametric” techniques needed in the “random walk in GNP” really are no longer needed; short order models to produce good long-term forecasts.
Journal of Economic Dynamics and Control, 12 (June/July 1988) 255-296. (With Argia M. Sbordone). This paper sits halfway between the “random walk in GNP” JPE and “permanent and transitory components” QJE. The “random walk” is univariate. Here, we realized that consumption could tell you a lot about the permanent component of GNP. Here, we use that insight in spectral and variance-ratio calculations. The answers are the same as in “permanent and transitory components”, but I now prefer the simpler VAR treatment in that paper. When GNP or stock prices are cointegrated with a random walk the subtle long-horizon and “nonparametric” techniques needed in the “random walk in GNP” really are no longer needed; short order models to produce good long-term forecasts.