Social activist, CEO of a small nonprofit, educator, talent agent, logistician, dietitian, fashion consultant, therapist and nurse. These are just a few of the roles mothers play in the lives of their children. And they are titles my wife has used, with a knowing smile in a number of social settings, to describe her role as a full-time mother.Some have attempted to estimate the economics of motherhood by adding up replacement costs of services mothers render, most recently yielding a market value of $112,962 per year.