Contacts between the Police and the Public: Three Tests of Convergent Validity

Abstract

The Police–Public Contacts Survey (PPCS) was required by law to provide information on the police use of force. Later the focus of the PPCS was expanded to include other contact, in particular, traffic stops. This research compares several of the PPCS findings (traffic stops and tickets, driving under the influence [DUI] arrests, and traffic accidents) to other pre‐existing measures of similar police activity. The findings suggest that the PPCS measurements are grossly disparate from the comparative measures and all point towards the conclusion that the PPCS has underestimated contact between the police and the public. Serious caution is suggested for use of the data in developing policy on police–citizen interactions.

Keywords:

• Police Stops
• Traffic Stops
• Motor Vehicle Stops
• DUI
• PPCS

Notes

[1] The exact method in which the number was arrived at was by subtracting the aggregate arrests of juveniles under 15 (840,000) from the juvenile arrest total (2,280,000) (equaling 1,440,000). The remaining arrests were for juveniles age 15–17, thus it was divided by three (equaling 480,000) and then the number for 15 year olds added to the under 15 arrest rate (equaling 1,320,000).

[2] For a copy of the survey and questions in the survey, see: Police Public Contact Survey, 1999 [United States]. Available at ICPSR (ICPSR 3151).

[3] The code book appears to account for multiple stops, as V28 includes individual codes between one and five stops (at 19). V63, which measures whether a traffic ticket was issued is provided only one space and has only two codes, 0 which is out of the universe or missing and 2 which indicates summonses issued. Thus, how many citations were issued does not appear to be measured.

[4] The procedures, inclusion, and exclusion of the data in the NCSC figures are very complex as many states have extensive footnotes addressing what is included and what is not in the total filings. The reader should consult these tables and examine figures to fully comprehend the complexity of the NCSC tables. It would be virtually impossible to reduce to article form.