This appendix provides supplementary information on characteristics of the System to Retrieve Information from Drug Evidence (STRIDE) cocaine data. STRIDE contains data on acquisitions of illegal drugs by the Drug Enforcement Administration (DEA) and the Metropolitan Police of the District of Columbia (MPDC). This discussion, which complements the description of the STRIDE data in Chapter 3, is oriented toward assessing the usefulness of STRIDE for constructing price indices for cocaine. The statistics reported in this appendix are obtained from the version of the STRIDE data that was supplied to the committee by the DEA. The DEA revises the contents of STRIDE from time to time, so the results reported here may not coincide precisely with results that are obtained from other versions of the data. The committee is confident, however, that the main qualitative conclusions reached using its version of STRIDE would also be reached using other versions.

There are over 160 DEA field offices in the United States. Each is responsible for a geographical area surrounding the city in which it is located. In any given year, STRIDE contains few or no records of purchases by most field offices. This is especially true for small purchases. In 1996, for example, 35 percent of the field offices recorded no purchases of cocaine base. Another 34 percent recorded only 1–9 purchases. Moreover, 55 percent of the offices recorded no purchases of cocaine base in quanti-