The argument of this careful but readable academic study is that how and how much society values children has changed drastically. . .and not necessarily rationally. Sociologist Zelizer focuses on the period 1870 to 1930, when, she says, the American child of most social classes was transformed from worker and wage earner to ""sacred"" object. Once the child had a role in productive life, and his or her worth was figured just like an adult's, according to earning power. But as children have become consumers of education and other products (and their parents' treasures), their value has increasingly been figured according to ""sentimental"" worth, ironically much higher. change is set into a broader context where noneconomic variables profoundly affect the market. Her sympathies lie in the ""novel field of sociological economics,"" but mercifully she doesn't get mired down there. Almost anyone concerned with children's welfare can learn something from this book of kids usefulness and uselessness. For example, even the most rabid opponent of exploitive child labor did not argue against appropriate work for youngsters. Paradoxically, distancing children from wage-earning and placing an exclusively emotional value on them has led to an ""increasing monetization and commercialization of children's lives."" The insuring of children's lives, the status of children under the law and in the adoption process are all analyzed, too. And the changed situation of many children today comes up. When the single parent or both parents have jobs, their children's labor is more and more needed at home. What is the fairest and healthiest way to pay them for their work? In sum, seminal background work for exploring this important matter, and working toward conclusions.