The 2015 Predicted Crime Rates Application is based on Chapter 4 of the 2015 California Crime Report. In the report ILSSC researchers make a forecast of the expected violent and property crime rate for the cities in Southern California.
We used a statistical model that allows us to make forecasts of the level of violent crime and property crime in the Southern California cities next year (2017). Our statistical models take into account the level of crime in these cities over the last 15 years, and how it has been changing, to make forecasts of how much violent and property crime there will be in these cities next year. We assessed the quality of our model on crime data from 1970 to 2010, and found that the average correlation between our projection of the property crime rate and the actual property crime rate was .89 over these prior years. The average correlation of our violent crime projection with the actual level was .95 over these prior years. So our model appears to do a reasonable job projecting crime levels forward in time. Nonetheless, we caution the reader that the forecasts for individual cities have a confidence interval around the predicted value.