Figure 3-2 National Crime Victimization Survey and Uniform Crime Reports estimates of serious violent crimes, 1973–2005

NOTES: Serious violent crimes include rape, robbery, aggravated assault, and homicide; homicide estimates from the UCR are added to the NCVS series. “NCVS Actual” includes crimes not reported to the police as well as those that are (“NCVS Reported”). NCVS estimates before 1993 are based on data year; for 1993 and later years collection year is used (see Table C-2).

SOURCE: National Crime Victimization Survey, Bureau of Justice Statistics and Uniform Crime Reports, Federal Bureau of Investigation. Data from http://www.ojp.gov/bjs/glance/tables/4meastab.htm [11/1/07].

nature of the offense makes it difficult to claim that UCR data alone could be a sufficient indicator for estimating current levels of “crime.”

If the goal is to assess long-term trends in crime, then a high correlation between UCR and NCVS trends would suggest that either data series would serve as a reasonable proxy for some analytical purposes. McDowall and Loftin (2007) assessed the correlations between UCR and NCVS national trends for index crimes for the period 1973–2003. Using a correlation standard of 0.80 or higher to indicate sufficient agreement in trends, they found that only two crimes came close to or exceeded this standard: robbery (r = 0.76) and burglary (r = 0.93). The next highest correlation was found for motor vehicle theft (r = 0.67). However, the remaining crime types exhibited much lower or even negative correlations. For larceny theft, the correlation was weak (r = 0.20), and for rape and assault, the correlations were negative (r = −0.16 and r = −0.21, respectively) (McDowall and Loftin, 2007:101). Like current level estimates, the trend correlations varied according to crime type. Analysts studying robbery and burglary can expect