Parenthood isnt a career-killer. In fact, economists with two or more kids tend to produce

more research, not less, than their one-child or childless colleagues. But female economists【C1】______can pay a price in terms of productivity after becoming mothers, especially【C2】______theyre young or unmarried. Thats according to a new research from the Federal Reserve Bank of St. Louis. There is widespread【C3】______that motherhood is【C4】______costly in terms of professional career advancement. "In particular, it is often【C5】______that the only way for young women to【C6】______a challenging career is to remain childless," they wrote. Our study of the academic labor market arrives at a somewhat less【C7】______picture: We do not observe a family gap in research productivity among female academic economists.【C8】______, motherhood-induced decreases in research productivity are less pronounced than usually purported. The authors in early 2012【C9】______about 10, 000 economists through the Research Papers in Economics online platform,【C10】______the academics answers with their publication records. They gauged an economists productivity【C11】______looking at their output: published research, weighted by journal【C12】______. Among their findings: Mothers of at least two children are,【C13】______, more productive than mothers of only one child, and mothers in general are more【C14】______than childless women. Fathers of【C15】______two children are also more productive than fathers of one child and childless men. Toward the end of their careers, however, childless men appear to be somewhat more productive than fathers of one child. Parenthood does appear linked to【C16】______productivity while the children are 12 and younger: mothers average a 17.4% loss, while fathers average a 5% loss. A female economist with three children, on average,【C17】______the equivalent of four years of research【C18】______by the time her kids become teenagers. Women who are married or in a【C19】______relationship do not have any drop in research productivity in the three years following childbirth. For single mothers, research output drops by roughly a third【C20】______the same period.

【C1】

A．in principle

B．in turn

C．in addition

D．in particular