We examine the robustness of persistence measurement to different seasonal adjustment procedures. The empirical analysis is based on U.S. data for real gross national product (GNP). Officially published data on U.S. GNP are seasonally adjusted by Census X-11. We find that this series gives...

Professional forecasts of aggregate U.S. consumption series strongly reject Robert E. Hall's (1978) random walk hypothesis. Band spectrum regressions show that low-frequency variations in growth ra tes of expenditures on nondurables and services, defined as cycles takin g more than two years to...