Detecting Anomalies in Data on Government Violence

Can data on government coercion and violence be trusted when the data are generated by state itself? In this paper, we investigate the extent to which data from the California Department of Corrections and Rehabilitation (CDCR) regarding the use of force by corrections officers against prison inmates between 2008 and 2017 conform to Benford’s Law. Following a growing data forensics literature, we expect misreporting of the use-of-force in California state prisons to cause the observed data to deviate from Benford’s distribution. Statistical hypothesis tests and further investigation of CDCR data—which show both temporal and cross-sectional variance in conformity with Benford’s Law—are consistent with misreporting of the use-of-force by the CDCR. Our results suggest that data on government coercion generated by the state should be inspected carefully before being used to test hypotheses or make policy.

当数据由政府自身生成时，关于政府强制行为与暴力事件的相关数据是否具备可信度？本论文针对2008年至2017年间，加州惩教与康复部（California Department of Corrections and Rehabilitation, CDCR）发布的惩教人员对监狱在押人员使用武力的相关数据，探究其在多大程度上符合本福德定律（Benford’s Law）。依托不断涌现的数据取证相关研究文献，我们推测加州州立监狱中使用武力事件的误报行为，会使得观测数据偏离本福德分布。通过统计假设检验以及对CDCR数据的进一步分析——结果显示该数据在符合本福德定律方面同时存在时间维度与横截面维度的差异——我们的结论与CDCR存在使用武力事件误报的推断相一致。本研究结果表明，在使用由政府自行生成的政府强制行为相关数据开展假设检验或制定政策前，应当对其进行审慎核查。