Systematic Measurement Error with State-Level Crime Data: Evidence from the “More Guns, Less Crime” Debate

Researchers have recently been cautioned regarding error in the Uniform Crime Reports’ (UCR) “Crime by County” cross-sectional time-series data. These data were the basis for analyses of the effects of laws regarding shall-issue concealed carry weapons (CCW) permits on UCR crime rates in the controversial book More Guns, Less Crime (MGLC). The authors conduct a critical analysis of the state-level data used in that study, compare it to readily available state-level UCR data, and discuss issues that may unduly influence the MGLC parameter estimates. Using alternative data, they reestimate the MGLC models, finding that the majority of the MGLC state-level findings are mere artifacts of reporting error and data anomalies resulting from the use of aggregated UCR “Crime by County” data. The authors conclude that any inferences regarding the effects of concealed carry weapons laws on crime rates drawn from analyses of the MGLC state-level data are seriously flawed.