Quantifying black crime: relative offending rates
Jan 4th, 2012 by Unamused
Last time, we showed how to correct the erroneous calculations by the Task Force on Race and the Criminal Justice System in its 2011 “Preliminary Report on Race and Washington’s Criminal Justice System.”
In our sample calculation, for robbery, we found that from 2004–2008, after combining single- and multiple-offender victimizations,
- there were at least 2.0 times as many black robbery offenders as white and Hispanic (W&H) robbery offenders,
- at least 60% of robbery offenders were black, and
- the black robbery rate was at least 13 times the W&H robbery rate.
Note that we obtained these minima by assuming that no robbery involved more than four offenders.
Today, we present our first set of results:
- The black offending rate by number of offenders (i.e., separating single- and multiple-offender victimizations) for six violent crime categories, expressed as a multiple of the corresponding W&H rate, 2004–2008. For example, we found that the black single-offender robbery rate was 8.5 times the W&H single-offender robbery rate, and the black multiple-offender robbery rate was 16 times the W&H multiple-offender robbery rate.
- The minimum overall black offending rate (combining single- and multiple-offender victimizations) for the same six categories, expressed as a multiple of the corresponding W&H rate, 2004–2008. For example, we found that the overall black robbery rate was at least 13 times the overall W&H robbery rate.
The crime categories are: rape and sexual assault (“rape/sex. assault”), robbery, aggravated assault (“agg. assault”), simple assault (“sim. assault”), violent crime of any of these types (“violence”), and completed — as opposed to attempted — violent crime of any of these types (“compl. violence”).
Our data on criminal victimization are from the National Crime Victimization Survey (NCVS), 2004–2008 (the five most recent years for which the survey’s complete data are available).
The graphs appear below. Note that the W&H rate is always 1.0. Also note that, under our assumptions, the maximum black offending rate is given by the corresponding black offending rate for multiple-offender victimizations (first graph, shaded bars). For example, we found that the overall black robbery rate was no more than 16 times the overall W&H robbery rate.