4. Consider the overlapping generations model. Let the number of young people born each period be constant, at N. The at money stock changes at rate "f 3:- 1, so that M} = TMtl- Each young person born in period t is endowed with 3; units of the consumption good when young and nothing when old. (a) 1|Write down equations that represent the constraints on rst and secondperiod consumption for a typical person. Combine these constraints into a lifetime budget constraint. {1.5%} [b] Draw the lifetime budget constraint on a diagram, with cl on the xaxis and c; on the vertical axis. [(15%)