Nancy Folbre, an economist at the University of Massachusetts, Amherst, argued in her 2008 book "Valuing Children" that forgone wages should be included in the cost of raising children.
For example, Folbre notes that men constitute more than 71% of the workforce in manufacturing (which was hit hard in the recession, and also hit with outsourcing to lower cost labor countries, increased automation, and increased foreign trade) and they make up less than 25% of the workers in health and education services (where jobs have risen slowly, but steadily).