[The original version of this paper appeared as a University of California San Diego working paper in 1990 but has since disappeared from the web. This version includes a new appendix.] This paper provides tables of critical values for some popular tests of cointegration and unit roots. Although...

This paper provides tables of critical values for some popular tests of cointegration and unit roots. Although these tables are necessarily based on computer simulations, they are much more accurate than those previously available. The results of the simulation experiments are summarized by...

This paper discusses model-based inference in an autoregressive model for fractional processes which allows the process to be fractional of order d or d-b. Fractional differencing involves infinitely many past values and because we are interested in nonstationary processes we model the data...