Date & Time: Friday, January 23, 2008, 14:30-15:30.
Venue: Ramanujan Hall

Title: Goodness-of-fit Testing Under Long Memory

Speaker: Hira L. Koul, Michigan State University

Abstract: In these two talks we shall discuss the problem of fitting a distribution function to the marginal distribution of a long memory process. It is observed that unlike in the i.i.d. set up, classical tests based on empirical process are relatively easy to implement. More importantly, we discuss fitting the marginal distribution of the error process in location, scale and linear regression models.

An interesting observation is that the first order difference between the residual empirical process and the null model can not be used to asymptotically to distinguish between the two marginal distributions that differ only in their means. This finding is in sharp contrast to a recent claim of Chan and Ling to appear in the Ann. Statist. that such a process has a Gaussian weak limit. We shall also proposes some tests based on the second order difference in this case and analyze some of their properties.

Another interesting finding is that residual empirical process tests in the scale problem are robust against not knowing the scale parameter.

The third finding is that in linear regression models with a non-zero intercept parameter the first order difference between the empirical d.f. of residuals and the null d.f. can not be used to fit an error d.f.

This talk is based on ongoing joint work with Donatas Surgailis.