Note, finally, that if there is a simultaneous increase in household income and net child price as a result of, say, expanding female employment opportunities and a rise in wages coupled with a tax on children beyond a certain number per family, there will be both an outward shift and downward rotation of the budget constraint line of Figure 6.9 to, say, dashed line cd. The result is a new utility-maximizing combination that includes fewer children per family (point g compared with point f). In other words, higher levels of living for lowincome families in combination with a relative increase in the price of children (whether brought about directly by fiscal measures or indirectly by expanded female employment opportunities) will motivate households to have fewer children while still improving their welfare. This is just one example of how the
economic theory of fertility can shed light on the relationship between economic development and population growth as well as suggest possible lines of policy.