Immigration and Crime: Is the Narrative Fact or Fiction?

Western Society of Criminology 2019

ILSSC will be attending the 46th annual Western Society of Criminology Meeting from February 7-9, 2019 in Honolulu, Hawai’i. There are three panels featuring work by ILSSC at WSC this year. Find out more information on the panels:
https://ilssc.soceco.uci.edu/western-society-of-criminology-2019

Predicted Crime Rates Application

The 2019 Predicted Crime Rates Application is based on Chapter 4 of the 2019 Southern 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 (2019). 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.

American Society of Criminology Meeting 2018

ILSSC will be attending the 74rd American Society of Criminology Meeting from November 14-17, 2018 in Atlanta, Georgia. There are four Complete Thematic Panels Sponsored by ILSSC at ASC this year. Find out more information on the panels:

ILSSC at the American Society of Criminology Meeting 2018

Southern California Crime Study

In the Southern California Crime Study (SCCS), we made an effort to contact each police agency in the Southern California region and request address-level incident crime data for the years 2005-2012. Many of the agencies were willing to share their data with us. As a consequence, we have crime data for 2,740 of the 3,852 tracts in the region, which cover 219 of the 341 cities and 83.3% of the region’s population.

Further information

The data come from crime reports officially coded and reported by the police departments. We classified crime events into 6 Uniform Crime Report (UCR) categories: homicide, aggravated assault, robbery, burglary, motor vehicle theft, and larceny. Crime events were geocoded for each city separately to latitude–longitude point locations using ArcGIS 10.2, and aggregated to various units such as blocks, block groups, and census tracts. The average geocoding match rate was 97.2% across the cities, with the lowest value at 91.4%. These data have been used in prior studies (see below).
In 2010:

  • Of 270,095 blocks, we have crime data for 208,091 (77.04%)
  • We have crime data covering population of 16,779,884 out of 20,149,002 total (83.28%)
  • 128,125 blocks have crime data in all years covering 11,122,770 population (55.2% of total population)
  • 150,341 blocks have crime data in all years but one, covering 12,442,179 population (61.75% of total population)