This paper develops a time domaine score statistic for testing fractional integration at zero and seasonal frequencies in quarterly time series models.

It is well known that, under some conditions, tests are asymptotically equivalent, and are optimal in the sense that the local power of these tests are equal to the maximum that can be achieved. However, in most practical situations, the density function f is unknown.

This paper develops a time domaine score statistic for testing fractional integration at zero and seasonal frequencies in quarterly time series models.

This paper applies an equilibrium search to study the transition from schooling to work of US high school graduates. We consider the case where there is heterogeneity in firm productivity and the number of firm types is discrete. For this case the estimation problem is non-standard and the...