“Religion is a good,” Chiswick told me in an interview. While it's unconventional to think of religion that way, the transaction of exchanging time and money for a particular experience retains certain core qualities whether that experience is religious or secular. For example, though it might seem more wholesome than buying a boat, paying for religious schooling is still a purchase of a luxury good. Heading to church or synagogue might make one feel more righteous and community-oriented than going golfing on a weekend morning, and that’s pretty much the point: The feelings and knock-on effects gathered from spending time in a certain way are part of the overall purchase.

This idea of the “full cost,” in money plus time, of an item can present a very different perspective on many issues in the Jewish community. For example, probably the issue most talked about in the intersection of economics and Judaism is precisely that issue of the cost of Jewish education. At many prominent schools, tuition has grown at a rate well above that of inflation in recent decades, and left it simply unattainable for even many upper-middle-class families without some tuition assistance. It is routine to find schools charging in excess of $30,000 a year where I live, in Manhattan, and tuition in excess of $20,000 a year is common throughout the rest of the New York/New Jersey area. In Maryland, where Chiswick lives, tuition will almost always be more than $10,000 a year. When one realizes that sum often needs to be paid for multiple kids, and always out of post-tax dollars, it can suddenly stretch even an income of $200,000. Indeed, at a recent presentation I attended about a new tuition-assistance program, the sample families given as benefiting from the program were assumed to have pre-tax incomes ranging from $185,000 to $325,000, and between two and three kids attending the school.

But in the most detailed numeric breakdown of Chiswick’s book, she shows that the full cost of day school can be a much less significant expenditure than it is often made out to be. Because Jewish day schools can save parents quite a lot of time over lower-priced alternatives, they may be nearly breaking even when compared to other options, depending on the value of their time.

Labor economists suggest that the value we place on our time is directly correlated with our incomes. “A worker who is paid by the hour knows that leaving work on hour early—whether to sleep, to go shopping, or to drive a Hebrew-school carpool—involves a reduction in income exactly equal to the hourly wage rate,” Chiswick writes, and therefore, “a person’s potential hourly earnings thus provide a good first approximation of the value of an hour spent in any activity.” A lawyer who earns $200 an hour will view the time required to pick up and drop off their kid at different schools as quite expensive.