arch and bilinearity as competing models for nonlinear dependence in this article we consider whether the wide acceptance of autoregressive conditional heteroscedasticity arch models may be at the expense of other nonlinear processes such as bilinear models we first propose a joint test for arch and bilinearity a nonnested test is then suggested to determine whether nonlinear dependence should be attributed to arch or bilinearity the tests are then applied to three series when generalized arch garch models are taken as the null hypothesis we fail to reject it for all the data series when bilinearity is taken as the null however it is rejected in two cases moreover an out of sample forecasting exercise shows that the garch model is superior the results therefore indicate a strong preference for the garch model

testing for nonlinear dependence in daily foreign exchange rates the purpose of this article is to investigate whether daily changes in five major foreign exchange rates contain any nonlinearities although the data contain no linear correlation evidence indicates the presence of substantial nonlinearity in a multiplicative rather than additive form further examination reveals that a generalized autoregressive conditional heteroskedasticity model can explain a large part of the nonlinearities for all five exchange rates copyright 1989 by the university of chicago

staggered contracts and the frequency of price adjustment this paper describes a methodology for measuring the frequency of price change in order to test the relevance of assuming prices to be set for discrete periods of time at overlapping intervals taylor 1980 has related the frequency of adjustment to the rigidity of the economy in responding to unanticipated events estimates of the frequency of price change are computed from data on the component parts of the deflator for personal consumption expenditure the results show a substantial decrease in the period between price changes during the middle 1960s and marked fluctuations in the 1970s the movements suggest changes in the rigidity associated with both changes in general price inflation and changes in the posture of the fiscal and monetary authorities

dynamic coalition formation and the core this paper presents a dynamic model of endogenous coalition formation in cooperative games with transferable utility tu the players are boundedly rational at each time step a player decides which of the existing coalitions to join and demands a payoff these decisions are determined by a best reply rule given the coalition structure and allocation in the previous period further the players experiment with myopically suboptimal strategies whenever there are potential gains from trade we establish an isomorphism between the set of absorbing states of the process and the set of core allocations and show that the process converges to one of these states with probability one whenever the core is non empty these results do not require superadditivity of the characteristic function and they carry over to the case of coalitional values depending on the coalition structure and to non transferable utility ntu games

conventional contracts intentional behavior and logit choice equality without symmetry abstract when coordination games are played under the logit choice rule and there is intentional bias in agents non best response behavior we show that the egalitarian bargaining solution emerges as the long run social norm without intentional bias a new solution the logit bargaining solution emerges as the long run norm these results contrast with results under non payoff dependent deviations from best response behavior where it has previously been shown that the kalai smorodinsky and nash bargaining solutions emerge as long run norms we complement the theory with experiments on human subjects results of which suggest that non best response play is payoff dependent and displays intentional bias this suggests the egalitarian solution as the most likely candidate for a long run bargaining norm

mistakes in cooperation the stochastic stability of edgeworth s recontracting in an exchange economywith a finite number of indivisible goods we analyze a dynamic trading process of coalitional recontracting where agents may make mistakes with small probability we show first that the recurrent classes of the unperturbed mistake free process consist of i all core allocations as absorbing states and ii cycles of non core allocations next we introduce a perturbed process where the resistance of each transition is a function of the number of agents that make mistakes do not improve in the transition and of the seriousness of each mistake if preferences are always strict we show that the unique stochasticallystable state of the perturbed process is the walrasian allocation in economies with indifferences non core cycles are sometimes stochastically stable while some core allocations are not

developments in the nonlinear analysis of economic series various aspects of the analysis of nonlinearities are surveyed in this paper a possibility of distinguishing between a low dimensional deterministic chaotic process and a white noise stochastic process using estimates of the correlation dimension is discussed it is concluded that there is no evidence of chaos as opposed to nonlinearity in the economic data the modes of testing for nonlinearity are briefly surveyed with particular attention paid to a new test based on a neural network specification it is found that aggregation can reduce nonlinearity and a definition of long memory is proposed that suggests a nonlinear generalization of cointegration

an evolutionary model of bargaining abstract individuals from two populations of bargainers are randomly matched to play the nash demand game they make their demands by choosing best replies based on an incomplete knowledge of the precedents and occasionally they choose randomly there is no common knowledge over the long run typically one division will be observed almost all of the time this stochastically stable division is close to the nash solution when all agents in the same population are alike when the populations are heterogeneous a generalization of the nash solution results if there is some mixing between the two populations the stable division is fifty fifty journal of economic literature classification number c78

a prospect theory nash bargaining solution and its stochastic stability abstract we consider the long run outcomes of bargaining games when players obey prospect theory we extend the evolutionary bargaining model of young 1993 to a two stage nash demand game two players simultaneously choose whether to exercise an outside option in the first stage and play the nash demand game in the second stage which will be reached only if neither player exercises the outside option we address the influence on the stochastically stable division of reference dependent preferences where the reference point is the value of the outside option we show that the division consistently differs from the nash bargaining solution under expected utility theory inspired by this we propose a prospect theory nash bargaining solution which coincides with the stochastically stable division

risk uncertainty and exchange rates this paper is motivated by two facts failure of log linear empirical exchange rate models of the 1970 s and the observed variability of risk premiums in the forward market rational maximizing models predict that changes in conditional variances of monetary policies government spendings and income growths affect risk premiums and induce conditional volatility of exchange rates i examine theoretically how changes in these exogenous conditional variances affect the level of the current exchange rate and attempt to quantify the extent that this channel explains exchange rate volatility using autoregressive conditional heteroscedastic models

stochastic stability under logit choice in coalitional bargaining problems abstract this study examines a dynamic process of n person coalitional bargaining problems we investigate the evolution of social conventions by embedding a coalitional bargaining setting in a dynamic process in each period a group of players may make some coalitional move that is forming a new team or negotiating the division of a surplus players revise their coalitions and surplus divisions over time in the presence of stochastic noise which leads players to make a suboptimal decision under a logit specification of choice probabilities we find that the stability of a core allocation decreases in the wealth of the richest player furthermore stochastically stable allocations are core allocations that minimize the wealth of the richest player

coalitions tipping points and the speed of evolution this study considers pure coordination games on networks and the waiting time for an adaptive process of strategic change to achieve ecient coordination although it is in the interest of every player to coordinate on a single globally ecient norm coalitional behavior at a local level can greatly slow as well as hasten convergence to eciency

menu costs and the neutrality of money a model of endogenous price adjustment under money growth is presented firms follow s s pricing policies and price revisions are imperfectly synchronized in the aggregate price stickiness disappears and money is neutral the connection between firm price adjustment and relative price variability in the presence of monetary growth is also investigated the results contrast with those obtained in models with exogenous fixed timing of price adjustment

on the short and long run efficiency of energy and precious metal markets this article contributes to the related literature by empirically investigating the efficiency of nine energy and precious metal markets over the last decades employing several pronounced models we test for both short and the long run efficiency using in addition to linear cointegration models nonlinear cointegration and error correction models ecms which allow the efficiency intensity to change per regime our findings can be summarized as follows i futures prices are found to be cointegrated with spot prices but they do not constitute unbiased predictors of future spot prices ii the hypothesis of risk neutrality is rejected iii the short run efficiency hypothesis is rejected suggesting that using past futures price returns improves the modeling and forecasting of future spot prices and iv the nonlinear modeling suggests the presence of two distinct regimes wherein the first regime the efficiency hypothesis is supported whereas in the second it is rejected the empirical findings have important implications for producers hedgers speculators and policymakers

dynamic duopoly with adjustment costs a differential game approach abstract this paper develops a differential game model of duopoly in which firms incur costs associated with how fast they change their level of output the analysis solves for a subgame perfect equilibrium to the model in which the steady state level of output lies strictly between the static cournot and perfect competition solutions furthermore we demonstrate that the limit game in which the speed of adjustment parameter approaches zero does not tend toward the static cournot equilibrium

coalitional stochastic stability in games networks and markets abstract this paper examines a dynamic process of unilateral and joint deviations of agents and the resulting stochastic evolution of social conventions our model unifies stochastic stability analysis in static settings including normal form games network formation games and simple exchange economies as stochastic stability analysis in a class of interactions in which agents unilaterally and jointly choose their strategies we embed a static setting in a dynamic process over time agents revise their strategies based on the improvements that the new strategy profile offers them in addition to the optimization process there are persistent random shocks on agents utility that potentially lead to switching to suboptimal strategies under a logit specification of choice probabilities we characterize the set of states that will be observed in the long run as noise vanishes we apply these results to examples of certain potential games

multivariate nearest neighbour forecasts of ems exchange rates exchange rate modelling has been a persistent puzzle for international economists forecasts from popular models for the exchange rate generally fail to improve upon the random walk out of sample while a multivariate nonparametric approach provides useful information about exchange rates the model produces forecasts superior to the random walk for only one of the three ems currencies examined using a statistic developed in mizrach 1991 i find that the forecast improvement a 4 5 percent reduction in mean squared error for the lira in daily returns is not statistically significant a cross validation exercise suggests that the improvement is also not robust

perturbed adaptive dynamics in coalition form games abstract players adaptively learn how to bargain a characteristic function describes the available surplus the underlying bargaining game extends the nash demand game by allowing subcoalitions to reach an agreement players demands must be multiples of a money unit we show that stochastically stable allocations ssa i e allocations that are most stable to unlikely errors are a subset of the core uniqueness does not obtain even when the money unit becomes arbitrarily small nonetheless every ssa is related to the allocation that maximizes the product of players utilities over the core i e constrained egalitarian solution for tu games journal of economic literature classification numbers c71 c72 c78

adaptive play in multiplayer bargaining situations we study the dual issues of allocation and coalition formation in a model of social learning for a class of economies which can be expressed in terms of a real valued characteristic function we first show that all self perpetuating allocations realized from a simple bargaining game must be core allocations although players make simultaneous demands for surplus and only on their own behalf following this we provide a sufficient condition under which the society eventually learns to divide the surplus according to some core allocation regardless of the initial history

markov puppy dogs and related animals abstract it is shown that steady state markov perfect equilibria of discrete time infinite horizon quadratic adjustment cost games differ from equilibria of their infinitely repeated counterpart games with zero adjustment costs even though no adjustment costs are paid in the steady state in contrast to continuous time games the limit of these equilibria as adjustment costs approach zero is the same as the equilibria of their static counterpart games a classification scheme is presented and it is shown that the taxonomy is identical to that of analogous two stage games such as those analyzed by fudenberg and tirole american economic review papers and proceedings 1984 74 361 366 this classification is useful in that it implies that steady state equilibria need not be explicitly calculated to analyze qualitatively the effects of adjustment costs in strategic environments it is also argued that estimated conjectural variations parameters may capture a well defined property of strategic interaction in a dynamic game

characterizing nonlinearities in business cycles using smooth transition autoregressive models during the past few years investigators have found evidence indicating that various time series representing business cycles such as production and unemployment may be nonlinear in this paper it is assumed that if the time series is nonlinear then it can be adequately described by a smooth transition autoregressive star model the paper describes the application of these models to quarterly logarithmic production indices for 13 countries and europe tests reject linearity for most of these series and estimated star models indicate that the nonlinearity is needed mainly to describe the responses of production to large negative shocks such as oil price shocks

the mis behaviour of the aggregate price level this paper investigates the response of the price level to random monetary shocks through a model of the fixed cost of changing a nominal price it shows that in an inflationary environment an expansionary monetary shock is accommodated faster than a contractionary monetary shock furthermore when the average rate of monetary expansion increases the lag in response to a positive shock decreases the study also proves that the relationship between the expected rate of inflation and the variance of real prices is positive only above a critical level of expected inflation the most striking result in this area appears in the work of caplin and spulber 1987 they show that in the aggregate when inflation is monotone stickiness disappears even when all firms follow a strict s s rule in their model since firms are uniformly distributed discontinuous price adjustment at the firm level does not create stickiness at the aggregate level caballero and engel 1992 extend this analysis to incorporate idiosyncratic shocks they show that in the presence of monotone idiosyncratic shocks the long run stationary distribution of prices is the uniform distribution but in the short run when the distribution of prices is arbitrary aggregate stickiness can result from firms discontinuous price adjustments in the present work the focus shifts i use a model where aggregate stickiness emerges naturally from firms discontinuous price setting to investigate the effects of the rate of inflation on aggregate stickiness this work shows that aggregate stickiness is negatively correlated with the rate of inflation the higher the rate of inflation the less sticky the response of the aggregate price level with respect to positive nominal shocks and the closer the economy approaches the caplin and spulber model therefore when modeling a dynamic inflation tax one must account not only for the decrease in the monetary base but also for the increase in the speed at which the aggregate price level 889

arch models properties estimation and testing abstract the aim of this survey paper is to provide an account of some of the important developments in the autoregressive conditional heteroskedasticity arch model since its inception in a seminal paper by engle 1982 this model takes account of many observed properties of asset prices and therefore various interpretations can be attributed to it we start with the basic arch models and discuss their different interpretations arch models have been generalized in different directions to accommodate more and more features of the real world we provide a comprehensive treatment of many of the extensions of the original arch model next we discuss estimation and testing for arch models and note that these models lead to some interesting and unique problems there have been numerous applications and we mention some of these as we present different models the paper includes a glossary of the acronyms for the models we describe

monopolistic competition and the effects of aggregate demand how important is monopolistic competition to an understanding of the effects of aggregate demand on output we ask the question at three levels can monopolistic competition by itself explain why aggregate demand movements affect output can it together with other imperfections generate effects of aggregate demand in a way that perfect competition cannot if so can it give an accurate account of the response of the economy to aggregate demand movements the answers are no yes and yes

inflation fixed cost of price adjustment and measurement of relative price variability theory and evidence in an interesting paper julio rotemberg 1983 extends the works of eitan sheshinski and yoram weiss 1977 and michael mussa 1981 to examine the aggregate consequences of monetary growth in an economy in which sellers incur a fixed cost of price adjustment the fixed cost prevents a continual adjustment of individual prices so each seller keeps his price constant in periods of discrete length increasing his price in discrete jumps at the end of these periods a central feature of the inflationary process is therefore that relative prices become dispersed around their means and the theory predicts that even a fully anticipated inflation increases the variability of relative prices the empirical evidence on this point does however appear to be mixed on the one hand richard parks 1978 and stanley fischer 1981a b 1982 conclude that anticipated inflation does increase relative price variability which fischer interprets as providing empirical support for the theory on the other hand mario blejer 1981 1983 and blejer and leonardo leiderman 1982 find that anticipated inflation has no effect or only a very weak effect on relative price variability which makes john taylor 1981 doubt the quantitative significance of the theory 2 this paper uses rotemberg s theoretical framework to demonstrate that the proxy for relative price variability adopted in the empirical literature does not properly capture the relative price variability that is caused by a fixed cost of price adjustment the methodology of the above cited studies is therefore not appropriate for evaluating the empirical relevance of the fixed cost theory and the divergence of their results is not surprising specifically the proxy which consists of the variance of the rates of price change between successive observations does not always increase with the anticipated inflation even with disaggregate data 3 the proxy decreases with the anticipated inflation in approximately half of any interval of inflation rates for which a seller adjusts his price no more than a given number of times between successive observations moreover the relationship between the anticipated inflation and the proxy depends on such extraneous factors as the timing of the observations a change in the timing may change a positive relationship between the anticipated inflation and the proxy to a negative one and vice versa the paper also proposes alternative more satisfactory measures of relative price variability and provides empirical support for the theoretical conclusions

conditional testing for unit root bilinearity in financial time series some theoretical and empirical results abstract this paper introduces a t ratio type test for detecting bilinearity in a stochastic unit root process it appears that such a process is a realistic approximation for many economic and financial time series it is shown that under the null of no bilinearity the test statistics are asymptotically normally distributed proofs of these asymptotic normality results require the gihman and skorohod theory for multivariate diffusion processes finite sample results describe speed of convergence power of the tests and possible distortions to unit root testing which might appear due to the presence of bilinearity it is concluded that the two step testing procedure suggested here the first step for the linear unit root and the second step for its bilinearity is consistent in the sense that the size of the step one test is not affected by the possible detection of bilinearity at step two the empirical part of the paper describes testing unit root bilinearity for 65 garch adjusted stock market indices from mature and emerging markets it is shown that for at least 70 of these markets the hypothesis of no unit root bilinearity has to be rejected

capacity investment preemption and commitment in an infinite horizon model the commitment value of capacity is analyzed in an infinite horizon duopoly model the paper focuses on the role of alternative behavioral assumptions about the ability of firms to commit to investment paths each firm s investment strategy in a feedback nash equilibrium is shown to be a decreasing function of its rival s current capacity this creates an incentive for a firm to expand its capacity to preempt subsequent rival investment in a precommitment equilibrium there are no incentives to invest preemptively as a consequence steady state capacity levels are greater in a feedback nash equilibrium than in a precommitment equilibrium copyright 1987 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

sticky prices in a dynamic oligopoly an investigation of s s thresholds abstract the strategic implications of costly price adjustment are investigated empirically i assume that managers are engaged in a state space game and ask if the dynamic considerations that arise when they condition their choices on the state cause prices to be more or less rigid than when players use more myopic pricing rules the answer to this question depends on a parametric specification of the problem that lends itself to empirical assessment the micro panel data used to investigate this issue consist of weekly prices sales costs and promotional activity for three brands of saltine crackers sold by four chains of grocery stores in a small us town i find that in this market strategic behavior exacerbates price rigidity the thresholds are wider and the time between changes is longer than would be observed in a more myopic setting

a noncooperative theory of coalitional bargaining the authors explore a sequential offers model of n person coalitional bargaining with transferable utility and with time discounting their focus is on the efficiency properties of stationary equilibria of strictly superadditive games when the discount factor delta is sufficiently large it is shown that delay and the formation of inefficient subcoalitions can occur in equilibrium the latter for some or all orders of proposer however efficient stationary equilibrium payoffs converge to a point in the core as delta approaches one strict convexity is a sufficient condition for there to exist an efficient stationary equilibrium payoff vector for sufficiently high delta

a noncooperative view of coalition formation and the core a noncooperative implementation of the core is provided for games with transferable utility the implementation obtained here is meant to reflect the standard motivation for the core as closely as possible in the model proposed time is continuous this idealized treatment of time is most amenable for capturing an essential feature of the core there is always time to reject a noncore proposal before it is consumated

adjustment of consumers durables stocks evidence from automobile purchases this paper tests an optimal s s rule in household durable purchases and examines directly the resulting aggregate expenditure dynamics the observed decision rule responds to income uncertainty and growth as predicted by an s s model resulting from transactions costs tests against liquidity constraints find that about half the households purchase according to an optimal s s rule aggregating the s s rule over households produces a cross section distribution of durables holdings the empirical distribution is similar to that predicted theoretically as is its response to aggregate shocks furthermore simulations of aggregate expenditure based on the household distribution exhibit dynamics consistent with those observed in the 1980s

testing for arch in the presence of additive outliers in this paper we investigate the properties of the lagrange multiplier lm test for autoregressive conditional heteroskedasticity arch and generalized arch garch in the presence of additive outliers ao s we show analytically that both the asymptotic size and power are adversely affected if ao s are neglected the test rejects the null hypothesis of homoskedasticity too often when it is in fact true while the test has difficulty detecting genuine garch effects several monte carlo experiments show that these phenomena occur in small samples as well we design and implement a robust test which has better size and power properties than the conventional test in the presence of ao s applications to the french industrial production series and weekly returns of the spanish peseta us dollar exchange rate reveal that sometimes apparent garch effects may be due to only a small number of outliers and conversely that genuine garch effects can be masked by outliers

recontracting and stochastic stability in cooperative games abstract an evolutionary style model of recontracting is given which guarantees convergence to core allocations of an underlying cooperative game unlike its predecessors in the evolution learning literature this is achieved without assumptions of convexity of the characteristic function or a reliance on random errors the stochastic stability properties of the model are then examined and it is shown that stochastically stable states solve a simple and intuitive minimization problem which reduces to maximizing a rawlsian swf for a common class of utility functions in contrast to previous analyses the stochastically stable state is unique for a broad class of utility functions

a lagrange multiplier test for garch models abstract this paper extends the lagrange multiplier lm test to testing noise disturbances against garch disturbances in the linear regression model the resulting lm test for the garch alternative is identical to the lm test for an arch alternative