American liberals sometimes hold up Sweden as a model of social order, equality of the sexes, and respect for parental responsibilities. Its welfare state offers excellent free or subsidized prenatal care, 480 days of paid leave for both natural and adoptive parents, and additional leave for moms who work in physically strenuous jobs. Swedish parents have the option to reduce their normal hours (and pay) up to 25% until a child turns 8.

But all this assistance comes at a steep cost. At 61.85%, Sweden has the highest personal...