Crime-clearance data for 1975-1977, released by Her Majesty's Inspectorate of Constabulary, were obtained for all 41 police forces in England and Wales, excluding the Metropolitan Police Force. The study identified several refined measures of police performance and compared these with the clearance rates; it then tested whether the wide variation between forces was reduced by the refinement. The study correlated the clearance rate with the following variables: crime rate and crime mix, demographic and socioeconomic variables, and numerous police variables. Police resources did affect force clearance rates, but the relationship was such that a 1-percent increase in police personnel would not produce a commensurate increase in the clearance rate. The clearance of most routine crime, as various research studies have shown, derives from the help given police by the public rather than from police efforts. Some improvement in clearance rates might result from modified methods of crime investigation. 3 tables and 20 references.