Discrimination based on race, ethnicity, national origin, gender, age, disability, gender orientation, and other characteristics continues to distort employers hiring decisions and thereby limit employment opportunities for historically excluded groups. Research in psychology, sociology, economics, and management provides insights concerning the mechanisms of bias and interventions to mitigate their effects, but important questions remain. The innovative research technique of matched pair testing offers laboratory-like controlled conditions in quasi-experiments in real-world hiring situations. We propose seven types of testing studies to advance conceptual understanding of hiring bias and improve hiring practices.