Lecture Notes for Macroeconomics I, 2004
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Macroeconomics II: Behavioural Macro Summer 2017
Johannes-Gutenberg University Mainz Bachelor of Science in Wirtschaftswissenschaften Macroeconomics II: Behavioural Macro Summer 2017 Klaus Wälde (lecture) and Jean Roch Donsimoni (tutorials) www.macro.economics.uni-mainz.de February 22, 2017 Part III How behavioural macro could look like 10 The plan We take three typical macroeconomic fields • — business cycle analysis — unemployment and — growth We get to know standard models that allow us to understand why there are • — business cycles — unemployment and — growth 164 We then replace our well-known but far-off-track homo oeconomicus by more emotional • counterparts We see how predictions in emotional (or behavioural) macro models differ from standard • predictions: what can we now understand that we did not understand earlier? Is this prediction in any sense meaningful i.e. can we empirically distinguish between the • extended version and the original one? (though one) 165 11 Unemployment and time inconsistency 11.1 Models of unemployment Macro I told us that we can distinguish between Models of labour supply (“voluntary unemployment”) • Traditional views of unemployment based on static models • Modern models of unemployment looking at the dynamics of a labour market (search and • matching models) 166 11.1.1 A reminder of voluntary unemployment ... understood as a labour supply decision The setup • — Consider an individual that values consumption c and leisure l and is described by 1/θ u (c, l) = c + (1 ) l , < 1, 0 < < 1 — Real budget constraint (wage expressed in units of consumption -
5 the AK Model
Economic Growth Models: A Primer /Student's Guide, Miguel Lebre de Freitas 5 The AK model “…a level effect can appear as a growth effect for long periods of time, since adjustments in real economies may take place over decades”. [Sachs and Warner]. Learning Goals: Understand why getting rid of diminishing returns one can obtain unceasing growth via factor accumulation. Distinguish the case with endogenous savings. Review different models were simple factor accumulation can generate endogenous growth. Acknowledge the empirical challenges raised by the abandonment of diminishing returns. 5.1 Introduction Along the previous chapters, we learned that, under diminishing returns, factor accumulation cannot, by itself, explain the tendency for per capita income to grow over time. For this reason, a sustained growth of per capita income can only be achieved in the neoclassical model by postulating an exogenous rate of technological progress. In this chapter it is shown that, by getting rid of diminishing returns on capital accumulation, one can obtain continuous growth of per capita income without the need to postulate an exogenous rate of technological progress. This result is shown in terms of the so- called AK model. The AK model differs critically from the Solow model in that it relies on a production function that is linear in the stock of capital. In this model, per capita income grows continuously in the equilibrium, without any tendency to stabilize. In that model, a rise in the saving rate produces a permanent increase in the growth rate of per capita income. This contrasts with the Solow model, where a rise in the saving rate only delivers only a “level effect”. -
Equilibrium Refinements
Equilibrium Refinements Mihai Manea MIT Sequential Equilibrium I In many games information is imperfect and the only subgame is the original game. subgame perfect equilibrium = Nash equilibrium I Play starting at an information set can be analyzed as a separate subgame if we specify players’ beliefs about at which node they are. I Based on the beliefs, we can test whether continuation strategies form a Nash equilibrium. I Sequential equilibrium (Kreps and Wilson 1982): way to derive plausible beliefs at every information set. Mihai Manea (MIT) Equilibrium Refinements April 13, 2016 2 / 38 An Example with Incomplete Information Spence’s (1973) job market signaling game I The worker knows her ability (productivity) and chooses a level of education. I Education is more costly for low ability types. I Firm observes the worker’s education, but not her ability. I The firm decides what wage to offer her. In the spirit of subgame perfection, the optimal wage should depend on the firm’s beliefs about the worker’s ability given the observed education. An equilibrium needs to specify contingent actions and beliefs. Beliefs should follow Bayes’ rule on the equilibrium path. What about off-path beliefs? Mihai Manea (MIT) Equilibrium Refinements April 13, 2016 3 / 38 An Example with Imperfect Information Courtesy of The MIT Press. Used with permission. Figure: (L; A) is a subgame perfect equilibrium. Is it plausible that 2 plays A? Mihai Manea (MIT) Equilibrium Refinements April 13, 2016 4 / 38 Assessments and Sequential Rationality Focus on extensive-form games of perfect recall with finitely many nodes. An assessment is a pair (σ; µ) I σ: (behavior) strategy profile I µ = (µ(h) 2 ∆(h))h2H: system of beliefs ui(σjh; µ(h)): i’s payoff when play begins at a node in h randomly selected according to µ(h), and subsequent play specified by σ. -
Lecture Notes
GRADUATE GAME THEORY LECTURE NOTES BY OMER TAMUZ California Institute of Technology 2018 Acknowledgments These lecture notes are partially adapted from Osborne and Rubinstein [29], Maschler, Solan and Zamir [23], lecture notes by Federico Echenique, and slides by Daron Acemoglu and Asu Ozdaglar. I am indebted to Seo Young (Silvia) Kim and Zhuofang Li for their help in finding and correcting many errors. Any comments or suggestions are welcome. 2 Contents 1 Extensive form games with perfect information 7 1.1 Tic-Tac-Toe ........................................ 7 1.2 The Sweet Fifteen Game ................................ 7 1.3 Chess ............................................ 7 1.4 Definition of extensive form games with perfect information ........... 10 1.5 The ultimatum game .................................. 10 1.6 Equilibria ......................................... 11 1.7 The centipede game ................................... 11 1.8 Subgames and subgame perfect equilibria ...................... 13 1.9 The dollar auction .................................... 14 1.10 Backward induction, Kuhn’s Theorem and a proof of Zermelo’s Theorem ... 15 2 Strategic form games 17 2.1 Definition ......................................... 17 2.2 Nash equilibria ...................................... 17 2.3 Classical examples .................................... 17 2.4 Dominated strategies .................................. 22 2.5 Repeated elimination of dominated strategies ................... 22 2.6 Dominant strategies .................................. -
A Politico-Economic Model of Aging, Technology Adoption and Growth Francesco Lancia and Giovanni Prarolo
A Politico-Economic Model of Aging, Technology Adoption and Growth Francesco Lancia and Giovanni Prarolo NOTA DI LAVORO 48.2007 APRIL 2007 KTHC – Knowledge, Technology, Human Capital Francesco Lancia, University of Bologna Giovanni Prarolo, University of Bologna and Fondazione Eni Enrico Mattei This paper can be downloaded without charge at: The Fondazione Eni Enrico Mattei Note di Lavoro Series Index: http://www.feem.it/Feem/Pub/Publications/WPapers/default.htm Social Science Research Network Electronic Paper Collection: http://ssrn.com/abstract=984242 The opinions expressed in this paper do not necessarily reflect the position of Fondazione Eni Enrico Mattei Corso Magenta, 63, 20123 Milano (I), web site: www.feem.it, e-mail: [email protected] A Politico-Economic Model of Aging, Technology Adoption and Growth Summary Over the past century, all OECD countries have been characterized by a dramatic increase in economic conditions, life expectancy and educational attainment. This paper provides a positive theory that explains how an economy might evolve when the longevity of its citizens both influences and is influenced by the process of economic development. We propose a three periods OLG model where agents, during their lifetime, cover different economic roles characterized by different incentive schemes and time horizon. Agents’ decisions embrace two dimensions: the private choice about education and the public one upon innovation policy. The theory focuses on the crucial role played by heterogeneous interests in determining innovation policies, which are one of the keys to the growth process: the economy can be discontinuously innovation- oriented due to the different incentives of individuals and different schemes of political aggregation of preferences. -
Lecture Notes General Equilibrium Theory: Ss205
LECTURE NOTES GENERAL EQUILIBRIUM THEORY: SS205 FEDERICO ECHENIQUE CALTECH 1 2 Contents 0. Disclaimer 4 1. Preliminary definitions 5 1.1. Binary relations 5 1.2. Preferences in Euclidean space 5 2. Consumer Theory 6 2.1. Digression: upper hemi continuity 7 2.2. Properties of demand 7 3. Economies 8 3.1. Exchange economies 8 3.2. Economies with production 11 4. Welfare Theorems 13 4.1. First Welfare Theorem 13 4.2. Second Welfare Theorem 14 5. Scitovsky Contours and cost-benefit analysis 20 6. Excess demand functions 22 6.1. Notation 22 6.2. Aggregate excess demand in an exchange economy 22 6.3. Aggregate excess demand 25 7. Existence of competitive equilibria 26 7.1. The Negishi approach 28 8. Uniqueness 32 9. Representative Consumer 34 9.1. Samuelsonian Aggregation 37 9.2. Eisenberg's Theorem 39 10. Determinacy 39 GENERAL EQUILIBRIUM THEORY 3 10.1. Digression: Implicit Function Theorem 40 10.2. Regular and Critical Economies 41 10.3. Digression: Measure Zero Sets and Transversality 44 10.4. Genericity of regular economies 45 11. Observable Consequences of Competitive Equilibrium 46 11.1. Digression on Afriat's Theorem 46 11.2. Sonnenschein-Mantel-Debreu Theorem: Anything goes 47 11.3. Brown and Matzkin: Testable Restrictions On Competitve Equilibrium 48 12. The Core 49 12.1. Pareto Optimality, The Core and Walrasian Equiilbria 51 12.2. Debreu-Scarf Core Convergence Theorem 51 13. Partial equilibrium 58 13.1. Aggregate demand and welfare 60 13.2. Production 61 13.3. Public goods 62 13.4. Lindahl equilibrium 63 14. -
Ordinary Differential Equations
Ordinary Di↵erential Equations Macroeconomic Analysis Recitation 1 Yang Jiao⇤ 1 Introduction We will cover some basics of ordinary di↵erential equations (ODE). Within this class, we deal with di↵erential equations, whose variable of interest takes derivative with respect to ˙ dYt time t.DenoteYt = dt ,whereYt can be a scalar or vector. A general explicit form of ODE is Y˙t = f(Yt,t)(1) 2 First-Order Di↵erential Equations Autonomous equation:y ˙t = f(yt), an equation is autonomous when it depends on • ↵ time only through the variable itself. Example: kt = skt δkt,wheres, ↵ and δ are constants. − c˙t Linear equation:y ˙t = atyt + bt,whereat and bt are taken as given. Example: = • ct 1 (r ⇢), where γ and ⇢ are parameters, while r is a given function of t. γ t − t Homogeneous: set the above linear di↵erential equation b =0.Thisterminologyalso • t applies to high-order di↵erential equations: e.g.y ¨t = gty˙t + htyt. Autonomous equation can be solved (illustrated) graphically, while linear equation admits analytical solution. 2.1 Analytical Solution A homogeneous di↵erential equation y˙t = atyt (2) Divide both sides by yt, y˙t = at (3) yt ⇤Please email me if you find errors or typos to [email protected]. All comments and suggestions are welcome and appreciated. 1 dlog(y ) t = a (4) ) dt t Therefore, t yt = C exp( asds)(5) Z0 where C is determined by boundary condition. A linear di↵erential equation y˙t = atyt + bt (6) Rearrange the above equation as y˙ a y = b (7) t − t t t Multiply both sides by exp( t a ds), we obtain − 0 s t R t t y˙ exp( a ds) a y exp( a ds)=b exp( a ds)(8) t − s − t t − s t − s Z0 Z0 Z0 That is t t d[yt exp( asds)] − 0 = b exp( a ds)(9) dt t − s R Z0 t t u y =exp( a ds)( b exp( a ds)du + C)(10) ) t s u − s Z0 Z0 Z0 where C is pinned down by boundary condition. -
Characterizing Solution Concepts in Terms of Common Knowledge Of
Characterizing Solution Concepts in Terms of Common Knowledge of Rationality Joseph Y. Halpern∗ Computer Science Department Cornell University, U.S.A. e-mail: [email protected] Yoram Moses† Department of Electrical Engineering Technion—Israel Institute of Technology 32000 Haifa, Israel email: [email protected] March 15, 2018 Abstract Characterizations of Nash equilibrium, correlated equilibrium, and rationaliz- ability in terms of common knowledge of rationality are well known (Aumann 1987; arXiv:1605.01236v1 [cs.GT] 4 May 2016 Brandenburger and Dekel 1987). Analogous characterizations of sequential equi- librium, (trembling hand) perfect equilibrium, and quasi-perfect equilibrium in n-player games are obtained here, using results of Halpern (2009, 2013). ∗Supported in part by NSF under grants CTC-0208535, ITR-0325453, and IIS-0534064, by ONR un- der grant N00014-02-1-0455, by the DoD Multidisciplinary University Research Initiative (MURI) pro- gram administered by the ONR under grants N00014-01-1-0795 and N00014-04-1-0725, and by AFOSR under grants F49620-02-1-0101 and FA9550-05-1-0055. †The Israel Pollak academic chair at the Technion; work supported in part by Israel Science Foun- dation under grant 1520/11. 1 Introduction Arguably, the major goal of epistemic game theory is to characterize solution concepts epistemically. Characterizations of the solution concepts that are most commonly used in strategic-form games, namely, Nash equilibrium, correlated equilibrium, and rational- izability, in terms of common knowledge of rationality are well known (Aumann 1987; Brandenburger and Dekel 1987). We show how to get analogous characterizations of sequential equilibrium (Kreps and Wilson 1982), (trembling hand) perfect equilibrium (Selten 1975), and quasi-perfect equilibrium (van Damme 1984) for arbitrary n-player games, using results of Halpern (2009, 2013). -
Chapter 3 the Basic OLG Model: Diamond
Chapter 3 The basic OLG model: Diamond There exists two main analytical frameworks for analyzing the basic intertem- poral choice, consumption versus saving, and the dynamic implications of this choice: overlapping-generations (OLG) models and representative agent models. In the first type of models the focus is on (a) the interaction between different generations alive at the same time, and (b) the never-ending entrance of new generations and thereby new decision makers. In the second type of models the household sector is modelled as consisting of a finite number of infinitely-lived dynasties. One interpretation is that the parents take the utility of their descen- dants into account by leaving bequests and so on forward through a chain of intergenerational links. This approach, which is also called the Ramsey approach (after the British mathematician and economist Frank Ramsey, 1903-1930), will be described in Chapter 8 (discrete time) and Chapter 10 (continuous time). In the present chapter we introduce the OLG approach which has shown its usefulness for analysis of many issues such as: public debt, taxation of capital income, financing of social security (pensions), design of educational systems, non-neutrality of money, and the possibility of speculative bubbles. We will focus on what is known as Diamond’sOLG model1 after the American economist and Nobel Prize laureate Peter A. Diamond (1940-). Among the strengths of the model are: The life-cycle aspect of human behavior is taken into account. Although the • economy is infinitely-lived, the individual agents are not. During lifetime one’s educational level, working capacity, income, and needs change and this is reflected in the individual labor supply and saving behavior. -
Chapter 4 the Overlapping Generations (OG) Model
Chapter 4 The overlapping generations (OG) model 4.1 The model Now we will briefly discuss a macroeconomic model which has most of the important features of the RA model, but one - people die. This small con- cession to reality will have a big impact on implications. Recall that the RA model had a few special characteristics: 1. An unique equilibrium exists. 2. The economy follows a deterministic path. 3. The equilibrium is Pareto efficient. The overlapping generations model will not always have these characteristics. So my presentation of this model will have two basic goals: to outline a model that appears frequency in the literature, and to use the model to illustrate some features that appear in other models and that some macroeconomists think are important to understanding business cycles. 1 2 CHAPTER 4. THE OVERLAPPING GENERATIONS (OG) MODEL 4.1.1 The model Time, information, and demography Discrete, indexed by t. In each period, one worker is born. The worker lives two periods, so there is always one young worker and one old worker. We’re going to assume for the time being that workers have perfect foresight, so we’ll dispense with the Et’s. Workers Each worker is identified with the period of her birth - we’ll call the worker born in period t “worker t”. Let c1,t be worker t’s consumption when young, and let c2,t+1 be her consumption when old. She only cares about her own consumption. Her utility is: Ut = u(c1,t) + βu(c2,t+1) (4.1) The worker is born with no capital or bond holdings. -
Money and the Welfare Cost of Inflation in an R&D-Growth Model
A Tale of Two Growth Engines: Interactive Effects of Monetary Policy and Intellectual Property Rights* Angus C. Chu, Ching-Chong Lai, and Chih-Hsing Liao Final Version: September 2018 * The authors would like to thank Juin-Jen Chang, Chi-Ting Chin, Fu-Sheng Hung, Yiting Li, Ming-Fu Shaw, and two anonymous referees for their insightful comments. The usual disclaimer applies. ANGUS C. CHU is a professor of economics at China Center for Economic Studies, School of Economics, Fudan University and a research fellow at Shanghai Institute of International Finance and Economics (E-mail: [email protected]). CHING-CHONG LAI is a Distinguished Research Fellow at the Institute of Economics, Academia Sinica, and a Chair Professor at the Department of Economics, National Cheng Chi University, Institute of Economics, National Sun Yat-Sen University, and Department of Economics, Feng Chia University (E-mail: [email protected]). CHIH-HSING LIAO is an associate professor at the Department of Economics, Chinese Culture University, (E-mail: [email protected]) A Tale of Two Growth Engines: Interactive Effects of Monetary Policy and Intellectual Property Rights ______________________________________________________________________________ Abstract How do intellectual property rights that determine the market power of firms influence the growth and welfare effects of monetary policy? To analyze this question, we develop a monetary hybrid endogenous growth model in which R&D and capital accumulation are both engines of long-run economic growth. We find that monetary expansion hurts economic growth and social welfare by reducing R&D and capital accumulation. Furthermore, a larger market power of firms strengthens these growth and welfare effects of monetary policy through the R&D channel but weakens these effects through the capital-accumulation channel. -
Government Spending in a Simple Model of Endogeneous Growth
Government Spending in a Simple Model of Endogeneous Growth The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Barro, Robert J. 1990. Government spending in a simple model of endogeneous growth. Journal of Political Economy 98(S5): 103-125. Published Version doi:10.1086/261726 Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:3451296 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA Government Spending in a Simple Model of Endogenous Growth Robert J. Barro Harvard Universityand National Bureau of Economic Research One strand of endogenous-growth models assumes constant returns to a broad concept of capital. I extend these models to include tax- financed government services that affect production or utility. Growth and saving rates fall with an increase in utility-type expendi- tures; the two rates rise initially with productive government expen- ditures but subsequently decline. With an income tax, the decen- tralized choices of growth and saving are "too low," but if the production function is Cobb-Douglas, the optimizing government still satisfies a natural condition for productive efficiency. Empirical evidence across countries supports some of the hypotheses about government and growth. Recent models of economic growth can generate long-term growth without relying on exogenous changes in technology or population. Some of the models amount to theories of technological progress (Romer 1986; this issue) and others to theories of population change (Becker and Barro 1988).