I study the effect of time allocation in a family on the macro behaviour of an economy. I use an overlapping generations model to describe an economy where children's human capital is affected by parental childcare time and where parents' preference for spending time with children are determined endogenously, via transmission of preferences between generations, within and across the families. The model is characterised by multiple Pareto-ranked steady-state equilibria, and, therefore, predicts that economies with similar fundamentals can exhibit significantly different macroeconomic performance in the long run. Furthermore, a positive network externality in childcare time results in an inefficiency of all competitive equilibria: too little time is spent with children, and, as a result, a competitive economy underperforms, compared to the first-best outcome. The social optimum is characterised by the strongest preference of parents for childcare time.