Distribution of covariates reported in 1994 by country*
| USA (%) | Britain (%) | Germany (%) | Denmark (%) | |
| Woman | 52.8 | 50.8 | 51.7 | 49.5 |
| Minority status | 16.5 | 4.5 | 9.5 | 4.4 |
| Single | 13.5 | 8.0 | 16.5 | 14.0 |
| Cohabiting | 69.5 | 82.7 | 69.8 | 76.5 |
| Formerly partnered | 17.0 | 9.3 | 13.7 | 9.5 |
| Lower secondary education | 4.3 | 19.9 | 21.4 | 22.6 |
| Upper secondary education | 44.7 | 43.4 | 53.7 | 38.9 |
| Post-secondary education | 51.0 | 36.7 | 24.9 | 38.5 |
| Employed | 80.8 | 77.9 | 76.9 | 80.1 |
| Unemployed | 3.9 | 5.3 | 7.5 | 10.8 |
| Out of the labour force | 15.3 | 16.8 | 15.6 | 9.1 |
| Routine occupational class | 16.9 | 17.1 | 15.1 | 13.9 |
| Below median adjusted household income | 44.7 | 42.6 | 34.8 | 29.1 |
| Number of respondents | 5202 | 4477 | 4991 | 3553 |
↵* Inverse probability weights applied.