Table 1. Average estimates of structural equation model parameters from various data sources.
| Birth cohort range | Model Parameter | (Co)siblings-in-law | Piblings | First cousins | First-cousins-once-removed | Households |
|---|---|---|---|---|---|---|
| 1800s–1830s | t2 | 5.86% (± 0.68%) | 5.85% (± 1.52%) | 4.63% (± 0.91%) | 3.21% (± 0.95%) | – |
| a | 0.883 (± 0.096) | 0.681 (± 0.123) | 0.750 (± 0.061) | 0.852 (± 0.103) | – | |
| β | 0.440 (± 0.013) | (1/2) | (1/2) | (1/2) | – | |
| csib | – | – | – | – | 0.0433 (± 0.0179) | |
| csp | – | – | – | – | 0.0659 (± 0.0083) | |
| 1840s–1870s | t2 | 5.19% (± 0.66%) | 5.47% (± 1.20%) | 3.79% (± 0.64%) | 1.96% (± 0.61%) | – |
| a | 0.881 (± 0.092) | 0.527 (± 0.114) | 0.637 (± 0.058) | 0.785 (± 0.080) | – | |
| β | 0.395 (± 0.025) | (1/2) | (1/2) | (1/2) | – | |
| csib | – | – | – | – | 0.0510 (± 0.0155) | |
| csp | – | – | – | – | 0.0504 (± 0.0079) | |
| 1880s–1910s | t2 | 4.79% (± 0.59%) | 7.19% (± 1.68%) | 5.47% (± 1.50%) | 2.90% (± 0.89%) | – |
| a | 0.888 (± 0.084) | 0.425 (± 0.044) | 0.532 (± 0.047) | 0.667 (± 0.055) | – | |
| β | 0.398 (± 0.020) | (1/2) | (1/2) | (1/2) | – | |
| csib | – | – | – | – | 0.0600 (± 0.0172) | |
| csp | – | – | – | – | 0.0436 (± 0.0050) |
The mean (± SD) of estimates across all gender combinations and across the indicated birth-decade cohorts were averaged. SD is for those estimates; per-estimate SEs were not considered here. “(1/2)” indicates a value imposed by the estimation technique. Source data for these calculations are plotted in Figure 4 and Figure 5, and are provided in Supplemental Data File 1.