learning by doing vs learning from others in a principal agent model abstract we introduce learning in a principal agent model of output sharing under moral hazard we use social evolutionary learning to represent social learning and reinforcement experience weighted attraction ewa and individual evolutionary learning iel to represent individual learning learning in the principal agent model is difficult due to the stochastic environment the discontinuity in payoffs at the optimal contract and the incorrect evaluation of foregone payoffs for iel and ewa social learning is much more successful in adapting to the optimal contract than standard individual learning algorithms a modified iel using realized payoffs evaluation performs better but still falls short of social learning

can government spending increase private consumption the role of complementarity abstract it is empirically observed that private consumption responds positively to fiscal shocks we offer an explanation for this stylized fact based on the idea of complementarity between public and private consumption

the behavior of the exchange rate in the genetic algorithm and experimental economies this paper studies the behavior of the exchange rate in the kareken wallace overlapping generations economy with two currencies in which decision rules are updated using the genetic algorithm the analysis shows that a stationary monetary equilibrium of the kareken wallace model is not stable under the genetic algorithm dynamics the fluctuations in the genetic algorithm exchange rate are driven by fluctuations in the portfolio fractions which change over time in response to the inequality between the rates of return on two currencies further both the genetic algorithm simulations and the experiments with human subjects were characterized by continuing fluctuations of the exchange rate with first period consumption values close to a stationary value

learning ricardian equivalence abstract this paper tests whether subjects learn to comply with the ricardian equivalence proposition in a life cycle consumption laboratory experiment our results suggest that ricardian equivalence does not hold on average tax changes have a significant and strong impact on consumption choice using individual consumption time series the behaviour of 56 of our subjects can be classified as inconsistent with the ricardian equivalence proposition classifying subjects according to rules of thumb that best describe their behaviour we find that subjects switch less to rules that theoretically violate ricardian equivalence in later rounds compared to earlier rounds this implies that some subjects learn to comply with ricardian equivalence by changing their consumption strategy however the aggregate effect of taxation on consumption persists even after eight rounds of repetition

can fiscal spending stimulate private consumption abstract empirically government expenditure shocks seem to crowd in private consumption while neoclassical and new keynesian models predict crowding out we derive conditions under which a government in utility specification in a sticky price model helps to reconcile theory and evidence

learning to bid the design of auctions under uncertainty and adaptation we examine auction design in a context where symmetrically informed adaptive agents with common valuations learn to bid for a good despite the absence of private valuations asymmetric information or risk aversion bidder strategies do not converge to the bertrand nash equilibrium strategies even in the long run deviations from equilibrium strategies depend on uncertainty regarding the value of the good auction structure the agents learning model and the number of bidders although individual agents learn nash bidding strategies in isolation the learning of each agent by flattening the best reply correspondence of other agents blocks common learning these negative externalities are more severe in second price auctions auctions with many bidders and auctions where the good has an uncertain value ex post

the effect of government spending on private consumption a puzzle the empirical finding that cyclical changes in government spending tend to be associated with positive responses of private consumption has been interpreted as a challenge for representative agent intertemporal optimizing theories which usually imply that the negative wealth effect of higher fiscal spending reduces the households consumption and leisure the present paper shows that the evidence can be explained by a standard real business cycle type model with a nonadditively separable utility function and a small intertemporal consumption elasticity higher fiscal spending can raise consumption and lower investment as in the data the nonseparable utility model is shown to imply the same consumption euler equation as a model with rule of thumb consumers who mechanically spend their income

why does private consumption rise after a government spending shock recent empirical evidence suggests that private consumption is crowded in by government spending this outcome violates existing macroeconomic theory according to which the negative wealth effect brought about by a rise in public expenditure should decrease consumption

fiscal stimulus and the role of wage rigidity abstract in this paper we study the impact of an expansion in public spending in an economy characterized by limited asset market participation and sticky wages the flexible wage version of the model implies strong expansionary effects on output and consumption but also a counterfactual increase in real wages the introduction of sticky wages besides being a realistic addition solves this problem and preserves the expansionary effects on output and consumption moreover once we introduce segmentation in the labor market sticky wages are even essential to obtain expansionary effects

nonseparable preferences fiscal policy puzzles and inferior goods nonseparable preferences over consumption and leisure can generate an increase in private consumption in response to government spending as found in the data in a frictionless business cycle model however the conditions on preferences required for these result to obtain hold if and only if the consumption good is inferior similarly positive co movement of consumption and hours worked occurs if and only if either consumption or leisure is inferior

the general equilibrium effects of fiscal policy estimates for the euro area abstract this paper describes a dynamic stochastic general equilibrium model featuring a fraction of non ricardian agents in order to estimate the effects of fiscal policy in the euro area the model takes into account distortionary taxation on labor and capital income and on consumption while expenditures are broken down into purchases of goods and services compensation of public employees and transfers to households a newly computed quarterly data set of fiscal variables is used our results point to the prevalence of mild keynesian effects of public expenditures in particular although innovations in fiscal policy variables tend to be rather persistent government purchases of goods and services and compensations for public employees have small and short lived expansionary effects on private consumption while innovations in transfers to households show a slightly more sizeable and lasting effect the effects are more significant on the revenue side decreases in labor income and consumption tax rates have sizeable effects on consumption and output while a reduction in capital income tax favors investment and output in the medium run finally our estimates suggest that fiscal policy variables contribute little to the cyclical variability of the main macro variables

using stock returns to identify government spending shocks this article explores a new approach to identifying government spending shocks which avoids many of the shortcomings of existing approaches the new approach is to identify government spending shocks with statistical innovations to the accumulated excess returns of large us military contractors this strategy is used to estimate the dynamic responses of output hours consumption and real wages to a government spending shock we find that positive government spending shocks are associated with increases in output hours and consumption real wages initially decline after a government spending shock and then rise after a year we estimate the government spending multiplier associated with increases in military spending to be about 1 5 over a horizon of 5 years

rule of thumb consumers meet sticky wages it has been argued that rule of thumb consumers substantially alter the determinacy properties of simple interest rate rules and the dynamics of an otherwise standard new keynesian model in this paper we show that nominal wage stickiness helps re establishing standard results key findings are that wage stickiness i affects the shape of determinacy regions in the parameters space restoring the relevance of the taylor principle for the conduct of monetary policy ii implies that a rise in consumption in response to an innovation in government spending is not a robust feature of the model

genetic algorithm learning and the cobweb model this paper presents the cobweb model in which competitive firms in a market for a single good use a genetic algorithm to update their decision rules about next period production and sales the results of simulations show that the genetic algorithm converges to the rational expectations equilibrium for a wider range of parameter values than other algorithms frequently studied within the context of the cobweb model price and quantity patterns generated by the genetic algorithm are also compared to the data of experimental cobweb economies it is shown that the algorithm can capture several features of the experimental behavior of human subjects better than three other learning algorithms that are considered

explaining the facts with adaptive agents the case of mutual fund flows abstract this paper studies portfolio decisions of boundedly rational agents in a financial market learning is modeled via a genetic algorithm learning as modeled in this paper leads agents to hold too much risk as compared to the optimal portfolio of rational investors moreover adaptive agents exhibit an asymmetric response after positive and negative returns where the portfolio adjustment is more pronounced after negative returns it is demonstrated that investors in mutual funds show the same investment patterns as the adaptive agents in the model a model with entry and exit of agents is able to match the mutual fund data closely

on fiscal multipliers estimates from a medium scale dsge model this paper contributes to the debate on fiscal multipliers in the context of a structural model i estimate a micro founded dynamic stochastic general equilibrium model that features a rich fiscal policy block and a transmission mechanism for government spending shocks using bayesian techniques for us data

deep habits and exchange rate pass through abstract habit persistence at the level of individual goods varieties can explain incomplete exchange rate pass through to international prices deep habits give rise to a dynamic import demand function that leads to import price markup adjustments independently of nominal pricing frictions augmenting a two country dsge model with deep habits we obtain low exchange rate pass through to import prices even when nominal local currency price rigidities are negligibly low as nominal pricing frictions become more important the presence of deep habits further impedes the pass through of exchange rate fluctuations estimating model variants with limited information as well as full information methods we find that the deep habits model requires much lower degrees of nominal price rigidities to match empirical measures of the pass through of exchange rate fluctuations to us import prices

measuring prior sensitivity and prior informativeness in large bayesian models abstract in large bayesian models such as modern dsge models it is difficult to assess how much the prior affects the results this paper derives measures of prior sensitivity and prior informativeness that account for the high dimensional interaction between prior and likelihood information the basis for both measures is the derivative matrix of the posterior mean with respect to the prior mean which is easily obtained from markov chain monte carlo output we illustrate the approach by examining posterior results in the small model of lubik and schorfheide 2004 and the large model of smets and wouters 2007

the cyclical behavior of marginal cost and price the author examines the cyclical behavior of price marginal cost margins for u s manufac turing after 1956 short run marginal cost is markedly procyclical this is primarily due to procyclical overtime payments incurred beca use employment is not perfectly flexible in most industries output price fails to respond to the cyclical movement in marginal cost so price marginal cost margins are markedly countercyclical the res ults contradict business cycle theories that explain low production i n a recession by a high real cost of producing they support theories that explain low production in a recession by the inability of firms to sell their output copyright 1987 by american economic association

when does government debt crowd out investment summary we examine when government debt crowds out investment for the us economy using an estimated new keynesian model with detailed fiscal specifications and accounting for monetary and fiscal policy interactions whether investment is crowded in or out in the short term depends on policy shocks triggering debt expansions higher debt can crowd in investment for cutting capital tax rates or increasing government investment contrary to the conventional view no systematic relationships between real interest rates and investment exist explaining why reduced form regressions are inconclusive about crowding out at longer horizons distortionary financing is important for the negative investment response to debt copyright 2013 john wiley sons ltd

what are the effects of fiscal policy shocks we propose and apply a new approach for analyzing the effects of fiscal policy using vector autoregressions specifically we use sign restrictions to identify a government revenue shock as well as a government spending shock while controlling for a generic business cycle shock and a monetary policy shock we explicitly allow for the possibility of announcement effects i e that a current fiscal policy shock changes fiscal policy variables in the future but not at present we construct the impulse responses to three linear combinations of these fiscal shocks corresponding to the three scenarios of deficit spending deficit financed tax cuts and a balanced budget spending expansion we apply the method to us quarterly data from 1955 to 2000 we find that deficit financed tax cuts work best among these three scenarios to improve gdp with a maximal present value multiplier of five dollars of total additional gdp per each dollar of the total cut in government revenue 5 years after the shock copyright 2009 john wiley sons ltd

the relation between price changes and trading volume a survey this paper reviews previous and current research on the relation between price changes and trading volume in financial markets and makes four contributions first two empiri cal relations are established volume is positively related to the magnitude of the price change and in equity markets to the price change per se second previous theoretical research on the price volume relation is summarized and critiqued and major insights are emphasized third a simple model ofthe price volume relation is proposed that is consis tent with several seemingly unrelated or contradictory observations and fourth several directions for future research are identified

fiscal policy in the new neoclassical synthesis we analytically derive the cyclical effects of fiscal policy shocks in a new neoclassical synthesis model price stickiness has the consequence that a rise in government demand affects labor demand while at the same time the usual wealth effect boosts labor supply the strength of the demand effect depends on the response of the real interest rate governed by the monetary policy regime when the central bank controls money growth fiscal expansions are deflationary and might even be contractionary whereas output wages and inflation can increase when the rise in the real interest rate is dampened by an interest rate rule however price stickiness alone is not sufficient to explain a rise in consumption as predicted by keynesian theory

fiscal policy in general equilibrium this paper studies four classic fiscal policy experiments within a quantitatively restricted neoclassical model the authors main findings are as follows 1 permanent changes in government purchases can lead to short run and long run output multipliers that exceed one 2 permanent changes in government purchases induce larger effects than temporary changes 3 the financing decision is quantitatively more important than the resource cost of changes in government purchases and 4 public investment has dramatic effects on private output and investment these findings stem from important dynamic interactions of capital and labor absent in earlier equilibrium analyses of fiscal policy copyright 1993 by american economic association

propagation mechanisms for government spending shocks a bayesian comparison the inability of a simple real business cycle model to predict a rise in consumption in response to increased government expenditures observed in many empirical studies has stimulated the development of alternative theories of government spending shocks using the bayesian approach we evaluate the quantitative performance of five extant models and find that neither of the considered transmission mechanisms for government spending helps improve the fit of the baseline model moreover we find that consumption decreases in all estimated models in response to a rise in government spending

can public spending boost private consumption this paper analyses the effects on private consumption from an increase in productive and unproductive public spending a new keynesian model incorporating price and wage rigidities monetary policy and various fiscal rules is developed and estimated using bayesian techniques to capture the key cyclical characteristics of the us economy we find that price and wage rigidities along with a positive shock to the part of public spending that is productive are suficient to boost private consumption moreover we show that this initial positive reaction of private consumption is adequate to create a positive present value consumption multiplier for more than five years finally we show that our main results remain robust to changes in the monetary rule and the various methods of deficit financing

the effects of public spending externalities abstract we conduct a positive analysis on the effects of externalities produced by government spending to this effect we estimate using u s data an rbc model with two salient features first we allow government consumption to directly affect the marginal utility of consumption second we allow public capital to shift the productivity of private factors we provide an identification analysis that supports the strategy adopted for estimating the parameters governing these two channels on one hand private and government consumption are robustly estimated to be substitute goods because of substitutability labor supply reacts little to a government consumption shock so the estimated output multiplier is much lower than in models with separabilities on the other hand our results point towards public investment being unproductive

genetic algorithms and inflationary economies abstract this paper studies overlapping generations economies in which agents use genetic algorithms to learn correct decision rules the results of computer simulations show that a genetic algorithm converges to the unique monetary steady state in case of a constant money supply policy and to the low inflation stationary equilibrium in case of a constant real deficit financed through seignorage features of the genetic algorithm adaptation are compared to the performance of other learning algorithms and to the behavior observed in experiments with human subjects in the same olg environments

local identification in dsge models abstract the issue of identification arises whenever structural models are estimated lack of identification means that the empirical implications of some model parameters are either undetectable or indistinguishable from the implications of other parameters therefore identifiability must be verified prior to estimation this paper provides a simple method for conducting local identification analysis in linearized dsge models estimated in both full and limited information settings in addition to establishing which parameters are locally identified and which are not researchers can determine whether the identification failures are due to data limitations such as lack of observations for some variables or whether they are intrinsic to the structure of the model the methodology is illustrated using a medium scale dsge model

priors from general equilibrium models for vars abstract this paper uses a simple new keynesian dynamic stochastic general equilibrium model as a prior for a vector autoregression shows that the resulting model is competitive with standard benchmarks in terms of forecasting and can be used for policy analysis jel classification c11 c32 c53 key words bayesian analysis dsge models forecasting vector autoregressions 1 introduction dynamic stochastic general equilibrium dsge models are popular nowadays in macroeconomics they are taught in virtually every economics ph d program and represent a predominant share of publications in the field yet when it comes to policy making these models are scarcely used at least from a quantitative point of view the main quantitative workhorse for policy making at the federal reserve system is frb us a macro econometric model built in the cowles foundation tradition a style of macroeconomics that is no longer taught in many ph d programs 1 in their decision process fed policy makers rely heavily on forecasting they want to know the expected path of inflation in the next few quarters and by how much a 50 basis point increase in the federal funds rate would affect that path frb us offers answers to these questions answers that many macroeconomists would regard with suspicion given both the lucas 1976 critique and the fact that in general the restrictions imposed by cowles foundation models are at odds with dynamic general equilibrium macroeconomics sims 1980 general equilibrium models on the other hand have a hard time providing alternative answers the fact that these models are perceived to do badly in terms of forecasting as they are scarcely parameterized is perhaps one of the reasons why they are not at the forefront of policy making while progress is being made in the development of dsge models that deliver acceptable forecasts e g smets and wouters 2003 this paper proposes an approach that combines a stylized general equilibrium model with a vector autoregression var to obtain a specification that both forecasts well and is usable for policy analysis specifically the approach involves using prior information coming from a dsge model in the estimation of a vector autoregression loosely speaking this prior can be thought of as the result of the following exercise i simulate time series data from the dsge model ii fit a var to these data in practice we replace the sample moments of the simulated data by population moments computed from the dsge model solution since the dsge model depends on unknown structural parameters we use a hierarchical prior in our analysis by placing a distribution on the dsge model parameters a tightness parameter controls the weight of the dsge model prior relative to the weight of the actual sample markov chain monte carlo methods are used to generate draws from the joint posterior distribution of the var and dsge model parameters the paper shows that the approach makes even a fairly stylized new keynesian dsge model competitive with standard benchmarks in terms of forecasting real output growth inflation and the nominal interest rate the three variables that are of most interest to policy makers 2 up to this point our procedure borrows from the work of dejong ingram and whiteman 1993 and ingram and whiteman 1994 who are the first to use priors from dsge models for vars ingram and whiteman showed that prior information from the bare bones stochastic growth model of king plosser and rebelo 1988 is helpful in forecasting real economic activity such as output consumption investment and hours worked in addition to documenting the forecasting performance of a trivariate var with a prior derived from a monetary dsge model this paper makes two contributions that significantly extend the earlier work first we show formally how posterior inference for the var parameters can be translated into posterior inference for dsge model parameters

fiscal spending shocks endogenous government spending and real business cycles abstract we analyze a real business cycle model in which the government optimally chooses public investment and nonmilitary current expenditures to maximize the welfare of the representative private agent we characterize the optimal response of endogenous spending to shocks to technology and to military expenditures comovements between the components of government spending and other macroeconomic aggregates predicted by the model are compared with the corresponding comovements in the u s data the model captures the qualitative features of the relative volatilities of the components of government spending quite well but predicts too high correlations between the components of government spending and output

lottery markets design micro structure and macro behavior an ace approach abstract an agent based computational modeling of the lottery market is established in this paper to study the design issue in terms of the lottery tax rate as well as the emerging market behavior by using genetic algorithms and fuzzy logic lottery participants are modeled as autonomous agents who may endogenously adapt to exhibit behavioral properties consistent with well noticed behavior of lottery markets three major findings are presented first as anticipated a laffer curve is found in this model nonetheless the laffer curve has a flat top which indicates the non uniqueness of the optimal lottery tax rate second conscious selection behavior is also observed but it becomes weaker as time goes on third for the halo effect we observe exactly the opposite each of these three findings are then compared with available empirical results and the mechanism of genetic algorithms is further examined in light of the anti halo effect

new keynesian versus old keynesian government spending multipliers renewed interest in fiscal policy has increased the use of quantitative models to evaluate policy because of modelling uncertainty it is essential that policy evaluations be robust to alternative assumptions we find that models currently being used in practice to evaluate fiscal policy stimulus proposals are not robust government spending multipliers in an alternative empirically estimated and widely cited new keynesian model are much smaller than in these old keynesian models the estimated stimulus is extremely small with gdp and employment effects only one sixth as large and with private sector employment impacts likely to be even smaller we investigate the sensitivity of our findings with regard to the response of monetary policy the zero bound on nominal interest rates and the inclusion of an empirically relevant degree of rule of thumb behaviour in the new keynesian model in addition we relate our findings using estimated structural macroeconomic models to the recent literature using reduced form regression techniques