Audits are field experiments that combine traditional experiments with field research. The US Department of Housing and Urban Development pioneered the method in the 1970s when it conducted audits to test for racial discrimination in real estate markets. The approach has since been used in a variety of contexts, such as bank loan applications, negotiations at car dealerships, and hailing taxis. Pager relies on audit tests to measure and understand the consequences of race and criminality on Milwaukee’s entry-level labor market.

Experimenter effects refer to the possibility that tester expectations and behaviors can influence audit results in nonrandom ways. If auditors expect poor treatment from employers, for instance, they may behave defensively during job interviews. Pager describes experimenter effects as self-fulfilling prophecies, characterizing them as one of the most serious threats to the validity of audits.

The term invisible inequality describes inmates who are invisible to official indicators of economic and social well-being. Government employment statistics, for instance, leave prisoners out of their calculations, grossly overestimating the health of the economy by underreporting unemployment among young Black men. Pager cites the work of Bruce Western as the most comprehensive study of this phenomenon.