ADVANCED MACROECONOMICS I

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1 Professor Oliver Landmann 1 dvanced Macroeconomics DVNCED MCROECONOMICS I l. Shor Quesions (1 poin each) Reake Exam, Ocober 10, 2012 Mark he following saemens as rue () or False (F) on he firs page of he exam s shees. No explanaions required in his par. One poin for each correc answer. One poin subraced for each incorrec answer. Zero poins for omied quesions. 1. One of Kaldor s six sylized facs abou modern growh saes ha here are hardly any differences in he rae of growh of produciviy across counries. 2. In he Solow model, when capial per uni of effecive labor k is greaer han he seady-sae level of k, break-even invesmen exceeds acual invesmen. 3. In he Ramsey-Cass-Koopmans model, he condiion for a saionary capial sock per effecive labor inpu is a verical line in (k,c)-space. 4. In he RBC model, a permanen posiive produciviy shock leads o more oupu, more consumpion, bu less leisure. 5. he RBC heory is consisen wih he sylized fac ha real wages end o increase in booms and decrease in recessions. 6. In he Lucas model of imperfec informaion, boh m and E(p) are a shif parameer of he Lucas supply curve. 7. Real rigidiies reinforce he effecs of nominal rigidies. 8. Real rigidiies can sem from a fla MC curve and/or a high price elasiciy of individual firms demand. 9. he New Keynesian Phillips curve is a purely backward-looking represenaion of pricesickiness. 10. In he model of CGG, he Moneary Policy Rule is a line wih a negaive slope which is deermined by he slope of he shor-run Phillips curve and he relaive weigh of inflaion o oupu gap sabilizaion of he cenral bank s loss funcion.

2 Professor Oliver Landmann 2 Reake Exam dvanced Macroeconomics Ocober 10, 2012 II. 3 Problems (30 poins) Problem 1 (10 poins) Consider he Ramsey-Cass-Koopmans model of economic growh wih exogenous echnical progress and zero populaion growh. a) Wha is he dynamic response of c and k if here is a one-ime increase in he number of workers a some poin 0? Skech he adjusmen process in (k,c) space. b) Draw a diagram ploing he response of boh income and income per capia agains ime. Problem 2 (10 poins) In an empirical applicaion of he Real Business Cycle model, a researcher has specified he following heoreical model of echnology : (1) ~ ln = + g + ~ ~ where = ρ ( : ime; g, ρ 1 + ε, ( ε, : whie noise) : exogenuos Her empirical esimae of he ime-series process for yields (2) ln = ln 1 + ε, parameers) a) How do RBC heoriss measure? b) Wha is he meaning of whie noise? c) Wha does he numerical esimaion resul (2) imply for he values of g and ρ? (Hin: Express equaion (1) in erms of ln and ln -1.)

3 Professor Oliver Landmann 3 Reake Exam dvanced Macroeconomics Ocober 10, 2012 Problem 3 (10 poins) he diagram below illusraes Krugman s model of he baby-siing co-op. a) Which idea is expressed by he condiion C = L? b) Which idea is expressed by he verical line labelled L? c) Explain he difference beween Cn d ( M1) and Ce d ( M 1). d) Saring from poin, where does he co-op end up if he quaniy of scrip falls from M 0 o M 1 and if he price level is rigid? Explain.

4 Professor Oliver Landmann 1 dvanced Macroeconomics DVNCED MCROECONOMICS I Wiederholungsklausur, 10. Okober 2012 l. Kurze Fragen (jeweils 1 Punk) Kennzeichnen Sie die folgenden ussagen als Wahr (W) oder Falsch (F) auf dem Deckbla der Klausur. Keine Erklärungen sind in diesem eil verlang. Ein Punk bei korreker nwor. Ein Punk bzug für jede falsche nwor. Null Punke für ausgelassene Fragen. 1. Eine der sechs silisieren Faken nach Kaldor über modernes Wachsum besag, dass es kaum Unerschiede in den Produkiviäswachsumsraen der Länder gib. 2. Im Solow-Modell sind die break-even Invesiionen höher als die akuellen Invesiionen, wenn der Kapialsock pro effiziener rbeiseinhei größer is als das saionäre Gleichgewichsniveau von k. 3. Im Ramsey-Cass-Koopmans-Modell ergib die Bedingung für einen saionären Kapialsock pro effiziener rbei eine verikale Gerade im (k,c)-raum. 4. Im RBC Modell führ ein permanen anhalender posiiver Produkiviässchock zu höherem Oupu, mehr Konsum, aber weniger Freizei. 5. Die RBC heorie is konsisen mi dem silisieren Fak, dass Reallöhne in Booms seigen und in Rezessionen sinken. 6. Im Lucas Modell mi unvollsändigen Informaionen sind sowohl m als auch E(p) Verschiebungsparameer der Lucas ngebosfunkion. 7. Reale Rigidiäen versärken die Effeke von nominalen Rigidiäen. 8. Reale Rigidiäen können durch eine flache Grenzkosenkurve und/oder eine hohe Preiselasiziä der individuellen Nachfragefunkionen der Firmen ensehen. 9. Die Neukeynesianische Phillipskurve gib eine rein rückwärsschauende Beschreibung des Preissezungsverhalens der Firmen. 10. Im Modell nach Clarida/Galí/Gerler (JEL 1999) is die Geldpoliikregel eine Gerade mi einer negaiven Seigung, die durch die Seigung der kurzfrisigen Phillipskurve und das relaive Gewich von Inflaions- und Oupulückensabilisierung in der Verlusfunkion der Zenralbank besimm wird.

5 Professor Oliver Landmann 2 Wiederholungsklausur dvanced Macroeconomics 10. Okober 2012 II. 3 ufgaben (30 Punke) ufgabe 1 (10 Punke) Berachen Sie das Ramsey-Cass-Koopmans Wachsumsmodell mi exogenem echnischen Forschri und einem Bevölkerungswachsum von Null. a) Wie sehen die dynamischen Reakionen von c und k aus, falls es einen einmaligen nsieg in der nzahl der rbeier zum Zeipunk 0 gib? Skizzieren Sie den npassungsprozess im (k,c)-raum. b) Zeichnen Sie ein Diagramm, das sowohl das Einkommen als auch das Einkommen pro Kopf gegen die Zei abbilde. ufgabe 2 (10 Punke) In einer empirischen nwendung des Real Business Cycle Modells spezifier ein Forscher das folgende heoreische Modell der echnologie : (1) ~ ln = + g + ( : Zei; g, ρ : exogene ~ ~ wobei = ρ 1 + ε, ( ε, : weißesrauschen) Parameer) Die empirische Schäzung des Zeireihenprozesses für führ zu dem Ergebnis (2) ln = ln 1 + ε, a) Wie messen RBC-heoreiker? b) Was bedeue weißes Rauschen? c) Was implizier das Schäzergebnis (2) für die Were von g and ρ? (Hinweis: Drücken Sie Gleichung (1) in ln und ln -1 aus.)

6 Professor Oliver Landmann 3 Wiederholungsklausur dvanced Macroeconomics 10. Okober 2012 ufgabe 3 (10 Punke) Das folgende Diagramm illusrier Krugmans Modell einer Baby-siing Kooperaive. a) Welche Idee wird durch die Bedingung C=L ausgedrück? b) Welche Idee wird durch die verikale Gerade mi der Bezeichnung L ausgedrück? c) Erklären Sie den Unerschied zwischen Cn d ( M 1) und Ce d ( M 1). d) usgehend von Punk : Wo ende die Kooperaive, falls die Menge der Kupons von M 0 auf M 1 reduzier wird und das Preisniveau sarr is? Erklären Sie.

7 Professor Oliver Landmann 1 Reake Exam dvanced Macroeconomics Ocober 10, 2012 Soluion Ouline DVNCED MCROECONOMICS Reake Exam, Ocober 10, 2012 Soluion Ouline l. Shor Quesions (1 poin each) Mark he following saemens as rue () or False (F). 1. One of Kaldor s six sylized facs abou modern growh saes ha here are hardly any differences in he rae of growh of produciviy across counries. F 2. In he Solow model, when capial per uni of effecive labor k is greaer han he seadysae level of k, break-even invesmen exceeds acual invesmen. 3. In he Ramsey-Cass-Koopmans model, he condiion for a saionary capial sock per effecive labor inpu is a verical line in (k,c)-space. F 4. In he RBC model, a permanen posiive produciviy shock leads o more oupu, more consumpion, bu less leisure. 5. he RBC heory is consisen wih he sylized fac ha real wages end o increase in booms and decrease in recessions. 6. In he Lucas model of imperfec informaion, boh m and E(p) are a shif parameer of he Lucas supply curve. F 7. Real rigidiies reinforce he effecs of nominal rigidies. 8. Real rigidiies can sem from a fla MC curve and/or a high price elasiciy of individual firms demand. 9. he New Keynesian Phillips curve is a purely backward-looking represenaion of pricesickiness. F In he model of CGG, he Moneary Policy Rule is a line wih a negaive slope which is deermined by he slope of he shor-run Phillips curve and he relaive weigh of inflaion o oupu gap sabilizaion of he cenral bank s loss funcion.

8 Professor Oliver Landmann 2 Reake Exam dvanced Macroeconomics Ocober 10, 2012 Soluion Ouline II. 3 Problems (30 poins) Problem 1 (10 poins) one-ime increase in he labor supply a poin 0 amouns o an immediae fall in he capial-labor raio of he economy. s a consequence, per-capia income and percapia consumpion are reduced on impac. Bu since he seady-sae level of c and k are no affeced (boh demarcaion curves are unchanged), c and k gradually converge on he saddle pah o he old seady sae. ln per-capia income 0 ln income 0

9 Professor Oliver Landmann 3 Reake Exam dvanced Macroeconomics Ocober 10, 2012 Soluion Ouline Problem 2 (10 poins) a) RBC heoriss measure by means of he Solow residual which capures all componens of oupu growh rae ha are no measurable by facor growh. b) Whie noise is a serially uncorrelaed random process wih zero mean and finie variance. Srong whie noise is independen and idenically disribued. ~ c) Wriing he firs equaion of (1) for ime -1, solving for 1 and plugging his ino (1) gives an expression of (1) ) in erms of ln and ln -1. (see lecure noes). Comparing he coefficiens of his equaion wih he esimae in (2) yields g=0.02 and 0.8. Problem 3 (10 poins) a) he condiion C = L expresses he echnological fac ha one hour of baby-siing services consumed requires one hour of work on he par of he baby-sier (producion funcion). b) he verical line expresses inelasic labor supply. c) Noional demand Cn d ( M1) is he demand funcion of co-op members under full employmen, whereas effecive demand Ce d ( M1) akes ino accoun he effecive hours worked. d) Saring from poin, he co-op ends up in E if he quaniy of scrip falls from M 0 o M 1 and if he price level is rigid (muliplier effec, see Krugman s ex).