KEARNEY: That’s right. It was just a different period. The coal boom and bust happened in the 70s and 80s. What we find is that a 10 percent increase in earnings associated with the coal boom led to very similar-sized increases in married birth rates, as it did in the fracking boom: an 8 percent increase in marital birth rates for a 10 percent increase in earnings with the coal boom, and a 12 percent increase in married birth rates associated with the fracking boom. But the nonmarital birth response is very different: a 10 percent increase in earnings associated with the coal boom actually led to a reduction in nonmarital births. But a 12 percent increase in nonmarital births with a 10 percent increase in earnings associated with fracking. That’s where the response differed.