Local Employer Concentration, Unions, and Wages
| Dep. Var.: Log Avg. Wages | ||||||||
|---|---|---|---|---|---|---|---|---|
| County | CZ | |||||||
| SIC3 (1) | SIC3 (2) | SIC4 (3) | SIC4 (4) | SIC3 (5) | SIC3 (6) | SIC4 (7) | SIC4 (8) | |
| log(HHI, SIC3–county–year) | -0.017 | -0.014 | -0.017 | -0.015 | -0.017 | -0.015 | -0.016 | -0.017 |
| -4.51 | -3.94 | -4.51 | -4.30 | -4.18 | -3.63 | -4.44 | -4.02 | |
| log(emp, ind–local–year) | 0.033 | 0.032 | 0.030 | 0.031 | 0.033 | 0.032 | 0.031 | 0.031 |
| 36.55 | 33.67 | 41.99 | 40.57 | 33.42 | 30.63 | 35.95 | 33.52 | |
| log(labor productivity) | 0.072 | 0.069 | 0.067 | 0.064 | 0.071 | 0.068 | 0.067 | 0.063 |
| 47.92 | 46.39 | 46.26 | 41.98 | 39.92 | 34.27 | 35.09 | 30.48 | |
| Union | 0.186 | 0.221 | 0.154 | 0.205 | 0.268 | 0.162 | ||
| 14.13 | 3.89 | 12.35 | 12.00 | 4.22 | 10.91 | |||
| log HHI × Union | 0.036 | 0.028 | 0.022 | 0.022 | 0.038 | 0.031 | 0.024 | 0.028 |
| 4.19 | 3.00 | 2.38 | 2.35 | 4.06 | 3.09 | 2.70 | 2.68 | |
| log(plants per segment) | -0.007 | -0.008 | -0.005 | -0.007 | -0.006 | -0.007 | -0.005 | -0.006 |
| -5.15 | -5.88 | -4.82 | -4.75 | -4.38 | -4.76 | -4.25 | -4.06 | |
| log(plants per firm) | -0.007 | -0.006 | -0.008 | -0.007 | ||||
| -4.53 | -4.43 | -4.64 | -4.44 | |||||
| Plant age (/100) | 0.267 | 0.275 | 0.257 | 0.264 | 0.286 | 0.293 | 0.275 | 0.281 |
| 30.65 | 33.28 | 32.47 | 31.78 | 30.42 | 31.58 | 28.70 | 28.75 | |
| Year fixed effects | Y | Y | Y | Y | ||||
| Industry fixed effects | Y | Y | Y | Y | ||||
| Industry–year fixed effects | Y | Y | Y | Y | ||||
| Firm fixed effects | Y | Y | Y | Y | ||||
| Firm-year fixed effects | Y | Y | Y | Y | ||||
| Observations | 946,000 | 946,000 | 946,000 | 946,000 | 946,000 | 946,000 | 946,000 | 946,000 |
| R2 | 0.5714 | 0.6550 | 0.5849 | 0.6728 | 0.5720 | 0.6557 | 0.5862 | 0.6741 |
Notes: This table examines the interactive effects of employer concentration in a local labor market and industry union coverage rates on the wages of plants. The dependent variable is the log of average wages per worker as defined in Table 1. log(HHI), log(employment), and Union are lagged by one year. Columns 1–4 (Columns 5–8) present estimates using counties (CZs) to define local labor markets. Columns 1–2 and 5–6 (Columns 3–4 and 7–8) present estimates using three- and four-digit SIC industries to compute HHI, log(employment), and log(plants per segment). The t-statistics based on standard errors adjusted for sample clustering at the county or CZ level are reported below the coefficient estimates. The numbers of observations are rounded to the nearest thousand to follow the U.S. Census Bureau’s disclosure rules.