Are Children “Normal”?
研究美国非西班牙裔白人已婚夫妇的生育率与丈夫收入的关系，发现收入越高生育越多，支持孩子是正常品的观点，并利用1970年代能源价格冲击作为外生变量验证因果关系。
We examine Becker's (1960) contention that children are "normal." For the cross section of non-Hispanic white married couples in the U.S., we show that when we restrict comparisons to similarly-educated women living in similarly-expensive locations, completed fertility is positively correlated with the husband's income. The empirical evidence is consistent with children being "normal." In an effort to show causal effects, we analyze the localized impact on fertility of the mid-1970s increase in world energy prices - an exogenous shock that substantially increased men's incomes in the Appalachian coal-mining region. Empirical evidence for that population indicates that fertility increases in men's income.