A simple metric for predicting repeated intimate partner violence harm based on the level of harm of the index offence (… as long as a non-linear statistic is applied)

Purpose: A recent body of evidence investigated repeated intimate partner violence (IPV) using crime harm indices (the severity of victimisation), instead of crime counts (the number of additional victimisation incidents). Yet, the predictive utility of harm scores in IPV remains unclear – except that high-harm IPV is not usually followed by any additional IPV incidents. The authors take cases of repeat IPV from North Zealand Police, Denmark, to predict subsequent IPV harm and counts based on the level of harm of the first reported IPV offence. Design/methodology/approach: Using the Danish crime harm index (CHI) to estimate harm levels, non-linear regression models are applied (due to the non-linear nature of the data) to show that the CHI level of the index offence validly predicts gains in future CHI but does not predict IPV counts. Findings: The findings suggest that whilst high-harm IPV is a rare event and repeat high-harm IPV even rarer, when they do occur, escalation in harm is likely to occur. Practical implications: A simple metric of harm of the first reported IPV offence can validly predict future harm – however, scholars should apply more fitting analytical techniques than crude descriptive statistics, which fail to take into account the non-linear distribution of police records. Originality/value: This is the first study to show the value of predicting future harm based on prior harm in IPV.