Typical physics PhD admissions parameters limit access to underrepresented groups and US citizens but fail to predict doctoral completion.

Through a multivariate statistical analysis of a sample that includes roughly one in eight students who entered physics PhD programs from 2000-2010, we find that the traditional admissions metrics of undergraduate GPA and the Graduate Records Examination (GRE) Quantitative, Verbal, and Physics Subject Tests do not predict completion in US physics graduate programs with the efficacy often assumed by admissions committees. We find only undergraduate GPA to have a statistically significant association with physics PhD completion across all models studied. In no model did GRE Physics or GRE Verbal predict PhD completion. GRE Quantitative reached statistical significance in two of four model specifications, though the magnitude of its validity was limited: the PhD completion probability changes by less than 10% for students with 10th vs 90th percentile scores among test takers that were physics majors. Noting the significant race, gender, and citizenship gaps on the GRE tests, these findings indicate that the typical physics PhD admissions process is a deterrent to increasing representation of women and people of color: misuse of GRE scores selects against already-underrepresented groups and US citizens with tools that fail to robustly predict PhD completion.