In general, Lucy finds that throughout much of this century, female participation more closely approximates a "heterogeneous" model in which some women are
consistently in the labor force and others consistently out than a "homogeneous" model in which most women participate for a similar portion of the year or of the life cycle。





This means on the one hand that married women workers tend to have considerably more labor force experience than would be expected on the basis of the rather low
overall participation rates of married women that prevailed prior to World War II, but on the other hand that the subsequent large increases in their labor force participation were not accompanied by significant increases in their average level of labor force experience