Money, Income and Sunspots

Measuring Economic Relationships and the Effects of Differencing


Charles I. Plosser

University of Rochester, Rochester, NY 14627


G. William Schwert

University of Rochester, Rochester, NY 14627
and National Bureau of Economic Research


Journal of Monetary Economics, 4 (November 1978) 637-660


This paper discusses the question of whether economic time series regression models should be estimated between the levels or the changes of the variables of interest. We argue that many economic models should be estimated between the changes of the variables, rather than the levels of the variables. In addition, comparisons of the levels and changes regressions can be used as a crude test of model specification. These issues are illustrated with examples from Friedman and Meiselman's [1963] study of annual income and consumption and with data on sunspot activity from 1897-1958.

Key words: Differencing, Stationarity, Spurious regressions

JEL Classifications: C22


Cited 93 times in the SSCI through April 1996

© Copyright 1978, Elsevier
Return to Publications Page