Here's why. (1) The HP filter produces series with spurious dynamic relations that have no basis in the underlying data-generating process. (2) Filtered values at the end of the sample are very different from those in the middle, and are also characterized by spurious dynamics. (3) A statistical...

We study the usefulness of root tests as diagnostic tools for selecting forecasting models. Difference stationary and trend stationary models of economic and financial time series often imply very different predictions, so deciding which model to use is tremendously important for applied...

Seasonal adjustment procedures attempt to estimate the sample realizations of an unobservable economic time series in the presence of both seasonal factors and irregular factors. In this paper we consider a factor which has not been considered explicitly in previous treatments of seasonal...

Medical practitioners typically utilize the following protocol when advising pregnant women about testing for the possibility of genetic disorders: Pregnant women over the age of 35 should be tested for Down syndrome and other genetic disorders; for younger women, such tests are discouraged...

Linear RE models typically possess a multiplicity of solutions. Consider, however, the requirement that the solution coefficients must not be infinitely discontinuous in the model's structural parameters. In particular, we require that the solutions should be continuous in the limit as those...

For an economy with altruistic parents facing productivity shocks, the optimal estate taxation is progressive: fortunate parents should face lower net returns on their inheritances. This progressivity reflects optimal mean reversion in consumption, which ensures that a long-run steady state...

For centuries, most international trade involved an exchange of complete goods. But, with recent improvements in transportation and communications technology, it increasingly entails different countries adding value to global supply chains, or what might be called quot;trade in tasks.quot; We...

A large literature has developed quantitative versions of the Eaton and Gersovitz (1981) model to analyze default episodes on external debt. In this paper, we study whether the same framework can be applied to the analysis of debt crises in which domestic public debt plays a prominent role. We...

A century ago, everyone thought time and distance were well defined physical concepts. But neither proved absolute. Instead, measures/reports of time and distance were found to depend on one%u2019s reference point, specifically one%u2019s direction and speed of travel, making our apparent...