the frequency with which they check. The data show that nearly 50 percent of employers in Los
Angeles in 2001 use a private source to check criminal backgrounds of applicants, while nearly
40 percent of them use criminal justice agencies such as the attorney general office and the
police. Interestingly, only 6 percent of employers gather this information by asking the applicant
themselves. The patterns for those employers that always or sometimes check are nearly
identical to those just described, except that firms that sometimes check are slightly more likely
to use private sources and criminal justice agencies than those that always check.
The data in Figure 7 does suggest that the availability of low-cost criminal background
checking services has played a part in the increase in checking over time, especially since there
were few such services to do this checking in the early 1990s. Of course, the increasing
availability of these services may have allowed the latent demand for these services by
employers to be actualized. Moreover, this demand may have been increasing over the 1990s as
employers awareness of the growing presence of ex-offenders in the low-skill labor supply likely
increased as well.
Figure 8 shows employers responses to the question of when they conduct criminal
background checks stratified by their responses to the frequency with which they check. Figure
8 shows that the vast majority of employers who check criminal backgrounds do so before they
fill the position. About 20 percent of employers check criminal backgrounds after they have
filled the position, while a small fraction, about 5 percent, check some other time. Though not
shown here, our data also show that employers who check after they have filled the position
mostly do so during the employees’ probationary period. These patterns hold both for those
employers that check always and those that check sometimes.