Modelos Econômicos e Choques

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Moniteria 3 Problem Set 1 3.1 1- Debt and Interest Rates Problema agente representativo: 00 max est In It s.t. b = y- I 2 C (1) 0 = + Mt ( y- r c) Condições de = = 1/ct = - = = + Mt = rb+p = - = rb+p (2) Ct loci : (2) b = - regioes d partir (2) = 0 b (1) b = > 2 regioes d partir de (1) b Mit CamScanner gescanntDiagrama 3.2 CA b=0 b Choque em assumindo CA original with i=0 shock Two possible paths: I I from above II from below b=0 11 b Mit CamScanner gescanntr 3.3 Additional / short descent, C t immediate increase in debt II C -br t II t -b I t 2- The Yeoman model a) The representative firm problem max P.Y s.t. = = PY aggregate market aggregate consumption = expenditure of i on its consumption The takes the L = + Mit CamScanner gescannt3.4 First Order Condition on = 0 + A2P di ) 1/2 1/2 - = 0 For itj : 2) ) = ) = Pj = Pj = 1/2 Back to original restriction : Pj P = Y 1/2 (1) = = S.' di = Pⱼ = Pj P 2 (2) b) For each Ci = eernings P Price level Li = Uᵢ = r r consumption Thus its problem is written as: max - P (1) = r (*) (*): Assuming FOC: 1/2 - = = (1/2) symmetric price Mit CamScanner gescannt3.5 = ( 2 = = = - 1/8 remember d) All Yeomans producing = Y= = ( = = C: - = Pi P - r = - = = - r e) 1st order approximation around = = = + = = = + 1/2 - = Considering of a single agent3.6 3- Choque com vigidez de preços a) I problems da firms é: max 00 Pt 2 2 It 0 mas é pl explicitor d leide movimento da de Logo: Hc = - 2 + µ V. Pt Pt b) Condições de 0 - Pt + = Pt = (1) dHc = - + r Pt L' Pt M ) = + = - (2) c) Steady -state ^ 0 L"d) 3.7 0 M Pt e) Choque e permanente em M (assumido M M M t 0 St M M M M' t Efeito de em Pt= 0 Θ V Pt Locus não "custo depende de Θ de no preço" No limite Θ Pt as Ajuste "instantâneo" Mit CamScanner gescannt