p.rm0 = p.rm; p.rm1 = (1 + 0.015)^(1/4) - 1; p.P0 = 1; p.P1 = 1; p.mbar0 = p.rm0/(1 - (1 + p.rm0)^(-p.D)); % minimum payment required per 1 of initial debt p.mbar1 = p.rm1/(1 - (1 + p.rm1)^(-p.D)); % minimum payment required per 1 of initial debt p.rm = []; p.mbar = []; p.rmgrid = [p.rm0; p.rm1]; p.Pgrid = [p.P0; p.P1]; p.rgrid = [1; 2]; % index for whether mortgage is old o rnew p.nr = 2; % number of possible mortgage contracts fprintf('\n'); fprintf('PV of savings from rate refi (discounted at old rm) = %9.2f\n', (p.mbar0 - p.mbar1)*(1 - (1 + p.rm0)^(-p.D))/p.rm0*p.thetam*p.hbar); fprintf('\n'); % Construct grids: sv = gridmake(sv, [1; 2]); sw = gridmake(sw, [1; 2]); svbar = gridmake(svbar, [1; 2]); cmax = bisect('savings', 1e-13, 1e5, p.lgrid, p, amin); % c that implies a' = amin cmin = bisect('savings', 1e-13, 1e5, p.lgrid, p, amax); % c that implies a' = amax cmax = repmat(cmax, p.nt*p.nr, 1); cmin = repmat(cmin, p.nt*p.nr, 1); Vbar = repmat(Vbar, p.nr, 1); for iter = 1 : 5 Vbarold = Vbar; EV = griddedInterpolant({p.agrid, p.tgrid, p.rgrid}, reshape(Vbar, p.na, p.nt, p.nr), intmeth, 'linear'); % solve consumption-savings choice c = solve_golden('wfunc_new', cmin, cmax, sw, EV, p); [~, aprime] = savings(c, sw, p); W = wfunc_new(c, sw, EV, p); Winterp = griddedInterpolant({p.lgrid, p.tgrid, p.rgrid}, reshape(W, p.nl, p.nt, p.nr), intmeth, 'linear'); % Solve discrete choice problem V = solveh_new(sv, Winterp, p); % Interpolate V(w, theta) Vinterp = griddedInterpolant({p.wgrid, p.tgrid, p.rgrid}, reshape(V, p.nw, p.nt, p.nr), intmeth, 'linear'); % Compute expected value and update vbar Vbar = zeros(p.na*p.nt*p.nr, 1); for i = 1 : p.ny Vbar = Vbar + wy(i)*Vinterp((1 + p.rl)*svbar(:,1) + y(i), svbar(:,2), svbar(:,3)); end fprintf('%4i %6.2e \n', [iter, norm(Vbar - Vbarold)/norm(Vbar)]); end for iter = 1 : 5000 Vbarold = Vbar; EV = griddedInterpolant({p.agrid, p.tgrid, p.rgrid}, reshape(Vbar, p.na, p.nt, p.nr), intmeth, 'linear'); % solve consumption-savings choice if mod(iter, 50) == 0 c = solve_golden('wfunc_new', cmin, cmax, sw, EV, p); end [~, aprime] = savings(c, sw, p); W = wfunc_new(c, sw, EV, p); Winterp = griddedInterpolant({p.lgrid, p.tgrid, p.rgrid}, reshape(W, p.nl, p.nt, p.nr), intmeth, 'linear'); % Solve discrete choice problem V = solveh_new(sv, Winterp, p); % Interpolate V(w, theta) Vinterp = griddedInterpolant({p.wgrid, p.tgrid, p.rgrid}, reshape(V, p.nw, p.nt, p.nr), intmeth, 'linear'); % Compute expected value and update vbar Vbar = zeros(p.na*p.nt*p.nr, 1); for i = 1 : p.ny Vbar = Vbar + wy(i)*Vinterp((1 + p.rl)*svbar(:,1) + y(i), svbar(:,2), svbar(:,3)); end if mod(iter, 50) == 0 fprintf('%4i %6.2e \n', [iter/50, norm(Vbar - Vbarold)/norm(Vbar)]); if norm(Vbar - Vbarold)/norm(Vbar) < 1e-7, break, end end end