Note: The standard deviations in employment at establishments employing UMETRICS doctoral recipients, at all U.S. establishments owned by R&D performing firms, and all U.S. establishments are 6,407, 3,661 and 2,362 respectively; the standard deviations in payroll per worker are $120,199, $56,252 and $44,327 respectively; the differences in employment size and payroll per worker are statistically significant. Payroll per worker is the average payroll (the total payroll divided by the number of employees) across all employees at the three types of establishments - all U.S. establishments, all U.S. establishments owned by R&D performing firms, and the establishments employing UMETRICS doctoral recipients (regardless of whether they are owned by R&D performing firms). National and R&D establishments are weighted by total establishment employment, while Doctoral Recipient establishments are weighted by the number of doctoral recipients employed.