Accession Number : AD0608567

Title :   A SPECTRAL STUDY OF 'OVERADJUSTMENT' FOR SEASONALITY.

Descriptive Note : Technical rept., no. 1,

Corporate Author : STANFORD UNIV CALIF

Personal Author(s) : Nettheim,Nigel F.

Report Date : 11 NOV 1964

Pagination or Media Count : 23

Abstract : The usual model for an economic time series contains an irregular factor assumed (except for strikes, etc.) to be random. A random series, of course, will have components of roughly equal magnitude at all frequencies; thus in particular a seasonal pattern and trend will by chance occur in such a series. Hence decomposition techniques should allow a certain amount of seasonality and trend to remain in the estimated irregular factor. This fact has not been taken into account by methods used to date, so it is not surprising that noticeable troughs appear in the spectrum of estimated irregular factors. This phenomenon is called 'overadjustment'. The present paper proposes a method for recovering the overadjustment and gives some preliminary empirical results. The procedure of overadjustment and recovery is regarded as a logical one in the absence of a method of decomposition using the spectrum directly. (Author)

Descriptors :   (*ECONOMICS, MATHEMATICAL ANALYSIS), MANPOWER, COMMERCE, PERIODIC VARIATIONS, PROBABILITY, MATHEMATICAL MODELS, GRAPHICS

Distribution Statement : APPROVED FOR PUBLIC RELEASE