TABLE A1.

Decomposition of changes in earnings inequality among married couples into components due to the association between spouses’ earnings:

Inequality Measure and Component	1967–70 (A)	2003–5 (B)	Difference (C) = (B) – (A)	% Change vs. (Dl) (D)	% of Total Association Component (E)
CV:
(Dl) Predicted	.451	.629	.178
(D2) No change in association among dual-earners	.460	.616	.155	12.7	44.6
(D3) + no change in husbands’ earnings × odds wives work	.470	.607	.137	23.0	36.2
(D4) + no change in % dual-earner couples	.468	.596	.127	28.5	19.2
Total					100.0
High-low inequality:
(Dl) Predicted	3.959	7.257	3.298
(D2) No change in association among dual-earners	3.987	7.018	3.031	8.1	27.6
(D3) + no change in husbands’ earnings × odds wives work	3.894	6.464	2.570	22.1	47.8
(D4) + no change in % dual-earner couples	3.806	6.137	2.332	29.3	24.7
Total					100.0
High-middle inequality:
(Dl) Predicted	.582	.736	.154
(D2) No change in association among dual-earners	.592	.721	.129	16.0	56.7
(D3) + no change in husbands’ earnings × odds wives work	.600	.721	.122	20.9	17.4
(D4) + no change in % dual-earner couples	.603	.714	.111	28.2	25.9
Total					100.0
Middle-low inequality:
(Dl) Predicted	6.804	9.860	3.056
(D2) No change in association among dual-earners	6.735	9.728	2.993	2.1	8.2
(D3) + no change in husbands’ earnings × odds wives work	6.495	8.959	2.464	19.4	68.8
(D4) + no change in % dual-earner couples	6.307	8.595	2.288	25.1	23.0
Total					100.0

Note.—Data are from the 1968–2006 March Current Population Surveys. Model definitions are given in table 2. In this table, the plus sign (+) indicates that constraints are being added to the previous model. For example, (D3) is “No change in association among dual-earners + No change in husbands’ earnings × odds wives work.”