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Understanding Crime Incidence Statistics: Why the UCR (Uniform Crime Reports) Diverges From the NCS (National Crime Survey)

NCJ Number
132446
Author(s)
A D Biderman; J P Lynch
Date Published
1991
Length
144 pages
Annotation
This monograph identifies factors that could cause the Uniform Crime Reports (UCR), which reports on police crime statistics, and the National Crime Survey (NCR), which focuses on victim reports of crime, to move in opposite directions and estimates the relative importance of these factors via series data.
Abstract
The book first describes the NCS and the UCR, followed by an examination of the time series of the UCR Index and the NCS for the years 1973 to 1986. This analysis assesses the extent to which the impression of discrepancy arises from differences in the scope of crimes that each series is designed to cover, the procedural differences in their construction of the crime events, and the different population counts each series uses for rate denominators. Another chapter examines the contributions of nonuniformities in measurement in the NCS and UCR to the differences in the time series. The analysis concludes that when the comparisons between the two series were confined to those components of each that deal with a common universe of events, when the same units were used for crime counts, and when rates for the two series were calculated on an equivalent population base, the two indicators showed the same directional changes in both the general trend over the 14 years and fluctuations from year to year. 15 tables, 11 figures, 78 references, appended supplementary information, and a subject index