bulls bears and market sheep abstract a deterministic excess demand model of stock market behavior is presented that generates stochastically fluctuating prices and randomly switching bear and bull markets

development fertility and childbearing age a unified growth theory during the last two centuries fertility has exhibited in industrialized economies two distinct trends the cohort total fertility rate follows a decreasing pattern while the cohort average age at motherhood exhibits a u shaped pattern this paper proposes a unified growth theory aimed at rationalizing those two demographic stylized facts we develop a three period olg model with two periods of fertility and show how a traditional economy where individuals do not invest in higher education and where income rises push towards advancing births can progressively converge towards a modern economy where individuals invest in higher education and where income rises encourage postponing births our findings are illustrated numerically by replicating the dynamics of the quantum and the tempo of births for swedish cohorts born between 1876 and 1966

statistical equilibrium wealth distributions in an exchange economy with stochastic preferences abstract we describe an exchange market consisting of many agents with stochastic preferences for two goods when individuals are indifferent between goods statistical mechanics predicts that goods and wealth will have steady state gamma distributions simulation studies show that gamma distributions arise for a broader class of preference distributions we demonstrate this mathematically in the limit of large numbers of individual agents these studies illustrate the potential power of a statistical mechanical approach to stochastic models in economics and suggest that gamma distributions will describe steady state wealths for a class of stochastic models with periodic redistribution of conserved quantities journal of economic literature classification numbers c15 c62 c73 d3 d5

ants rationality and recruitment this paper offers an explanation of behavior that puzzled entomologists and economists ants faced with two identical food sources were observed to concentrate more on one of these but after a period they would turn their attention to the other the same phenomenon has been observed in humans choosing between restaurants after discussing the nature of foraging and recruitment behavior in ants a simple model of stochastic recruitment is suggested this explains the herding and epidemics described in the literature on financial markets as corresponding to the equilibrium distribution of a stochastic process rather than to switching between multiple equilibria

profitability of time series momentum abstract we propose a continuous time heterogeneous agent model consisting of fundamental momentum and contrarian traders to explain the significant time series momentum we show that the performance of momentum strategy is determined by both time horizon and the market dominance of momentum traders specifically when momentum traders are more active in the market momentum strategies with short long time horizons stabilize destabilize the market and meanwhile the market under reacts over reacts in short run long run this provides profit opportunity for time series momentum strategies with short horizons and reversal with long horizons when momentum traders are less active in the market they always lose the results provide an insight into the profitability of time series momentum documented in recent empirical studies

fiscal policy with agents differing in altruism and ability this paper presents an overlapping generations model of growth with individuals differing in productivity and altruism within such a model wealth is entirely held in the steady state by the families with the highest degree of altruism we then look at the macroeconomic and distributive effects of three fiscal policies public debt pay as you go social security and estate taxation under plausible assumption we show that both public debt and social security are neutral a la ricardo but increase inequality we also show that a estate taxation can be pareto worsening even though it can foster income equality

on the specification of noise in two agent based asset pricing models abstract the paper is concerned with two recent agent based models of speculative dynamics from the literature one by gaunersdorfer and hommes 2007 and the other by he and li 2007 at short as well as long lags both of them display an autocorrelation structure in absolute and squared returns that comes fairly close to that of real data at a daily frequency the note argues that these long memory effects are to be ascribed to the stochastic specification of the price equation which despite the wide fluctuations in these models fails to normalize the price shocks under an appropriate respecification the long memory completely disappears it is subsequently shown that an alternative introduction of randomness which may be called structural stochastic volatility can restore the original properties and even improves upon them

the industrial dynamics of open innovation evidence from the transformation of consumer electronics abstract this paper addresses how the open innovation concept as recently coined by henry chesbrough can be analyzed from an industrial dynamics perspective the main proposition of the paper is that the specific modes in which different companies manage open innovation in regard to an emerging technology reflect their differential position within the innovation system in question the nature and stage of maturity of the technological regime and the particular value proposition pursued by companies the proposition is analyzed through an in depth study of the current transformation of sound amplification from linear solid state technology to switched or digital technology within the consumer electronics system of innovation the analysis especially addresses the complex interplay between technology entrepreneurs and incumbents and demonstrates that open innovation sometimes has to be conducted under conditions of high transaction costs

open innovation for sustainability lessons from the greenxchange experience an ictsd policy brief the following policy brief discusses the natural experiment of greenxchange in the context of open innovation open innovation is a phrase popularized by berkeley professor henry chesbrough who argues that firms should externalize r d and other innovative activity for the sake of technological advancement and greenxchange was a web based program allowing for firms to share their intellectual property for the sake of sustainable innovation under the open innovation paradigm our research indicates that the mild success of greenxchange demonstrates a gap between academic ideas and their utilization in practice

heterogeneous beliefs and adaptive behaviour in a continuous time asset price model abstract this paper extends the analysis of the seminal work of brock and hommes 1997 brock and hommes 1998 on heterogeneous beliefs and rational routes to randomness in discrete time models to a continuous time model of asset pricing the resulting model characterised mathematically by a system of stochastic delay differential equations provides a unified approach to deal with adaptive behaviour of heterogeneous agents and market stability impact of lagged price used by chartists to form their expectations for the underlying deterministic model we show not only that the result of brock and hommes on rational routes to market instability in discrete time holds in continuous time but also a double edged effect of an increase in lagged price used by the chartists on market stability for the stochastic model we demonstrate that the interaction and boundedly rational behaviour of heterogeneous agents can generate various market phenomena such as bubbles and crashes and replicate stylised facts including volatility clustering and long range dependence in volatility

bubbles crashes and endogenous expectations in experimental spot asset markets1 spot asset trading is studied in an environment in which all investors receive the same dividend from a known probability distribution at the end of each of t 15 or 30 trading periods fourteen of twenty two experiments exhibit price bubbles followed by crashes relative to intrinsic dividend value when traders are experienced this reduces but does not eliminate the probability of a bubble the regression of changes in mean price on lagged excess bids number of bids minus the number of offers in the previous period p pt a f b 1 o l supports the hypothesis that a e d the one period expected value of the dividend and that f 0 where excess bids is a surrogate measure of excess demand arising from homegrown capital gains losses expectations thus when bt 1 o goes to zero we have convergence to rational expectations in the sense of fama 1970 that arbitrage becomes unprofitable the observed bubble phenomenon can also be interpreted as a form of temporary myopia tirole 1982 from which agents learn that capital gains expectations are only temporarily sustainable ultimately inducing common expectations or priors tirole 1982 four of twenty six experiments all using experienced subjects yield outcomes that appear to the chart s eye to converge early to rational expectations although even in these cases we get 0 and small price fluctuations of a few cents that invite scalping

heterogeneous expectations boom bust housing cycles and supply conditions a nonlinear economic dynamics approach abstract we combine a standard stock flow housing market model incorporating explicit relationships between house prices the housing stock and the rent level with a parsimonious expectation formation scheme of housing market investors reflecting an evolving mix of extrapolative and regressive expectation rules the model results in a two dimensional discrete time nonlinear dynamical system based on realistic parameters the model is able to generate endogenous boom bust housing market dynamics with lasting periods of overvaluation and overbuilding we thus exploit our model to investigate how real forces in particular supply conditions interact with expectations driven housing market fluctuations

house prices bank instability and economic growth evidence from the threshold model abstract this paper examines the effects of house prices on bank instability when gauged at various levels of income growth bank stability may respond differently to house price changes or deviations from fundamental values in an economic boom environment than in a bust circumstance a threshold estimation technique developed by hansen 1999 is applied to a panel of 286 u s metropolitan statistical areas msas over the period 1990q1 2010q4 we consider two house price indicators the house price changes and the house price deviations from long run equilibrium the results suggest the existence of income growth threshold effects in the relationship between house prices and bank instability specifically there are two income growth thresholds when using the house price changes and one income growth threshold when the house price deviations are applied robustness results using the non msas sample from 1995q1 to 2010q4 provide further evidence of income growth threshold effects

testing for non linear structure in an artificial financial market abstract we present a stochastic simulation model of a prototype financial market our market is populated by both noise traders and fundamentalist speculators the dynamics covers switches in the prevailing mood among noise traders optimistic or pessimistic as well as switches of agents between the noise trader and fundamentalist group in response to observed differences in profits the particular behavioral variant adopted by an agent also determines his decision to enter on the long or short side of the market short run imbalances between demand and supply lead to price adjustments by a market maker or auctioneer in the usual walrasian manner our interest in this paper is in exploring the behavior of the model when testing for the presence of chaos or non linearity in the simulated data as it turns out attempts to determine the fractal dimension of the underlying process give unsatisfactory results in that we experience a lack of convergence of the estimate explicit tests for non linearity and dependence the bds and kaplan tests also give very unstable results in that both acceptance and strong rejection of iidness can be found in different realizations of our model all in all this behavior is very similar to experience collected with empirical data and our results may point towards an explanation of why robustness of inference in this area is low however when testing for dependence in second moments and estimating garch models the results appear much more robust and the chosen garch specification closely resembles the typical outcome of empirical studies

intensive and extensive margins of fertility capital accumulation and economic welfare abstract this paper investigates the impact of low fertility on long term capital accumulation and economic welfare we find that the impact differs depending on whether the low fertility arises from a decrease in the fertility of mothers the intensive margin of fertility or the motherhood rate the extensive margin of fertility we show that an increase in the fertility of mothers decreases the capital stock and economic welfare conversely we identify a u shaped relationship between the extensive margin of fertility and the capital stock because of the existence of two opposing effects such that the decline in fertility may reduce economic welfare furthermore we show that an intragenerational income redistribution policy can eliminate the welfare loss resulting from the incomplete market

representativeness of news and exchange rate dynamics abstract guided by psychological evidence we develop a behavioral exchange rate model in which investors perception of fundamental shocks switches between two states according to the representativeness heuristic agents underestimate the informational content of news in calm periods whereas they overreact to news if they encounter a series of distinct exchange rate changes simulations indicate that the model mimics the behavior of actual exchange rates quite well for instance we observe fat tails for the distribution of the returns and volatility clustering

financial crises and regime dependent dynamics abstract generalized with the regime dependent beliefs and regime switching dynamics the simple market maker framework established by day and huang 1990 is capable to model all types of crises that is sudden crisis disturbing crisis and smooth crisis and to offer economic and dynamic justifications on how and why these crises appear moreover the model simulations verify the salient qualitative and statistical properties commonly observed in the real financial data such as fat tails volatility clustering long range dependence leverage effect and other stylized facts additionally the model replicates the various chart patterns widely applied in the technical analysis

fiscal policy in a growth model with both altruistic and nonaltruistic agents this paper examines the long run behavior of an overlapping generations model with a population consisting of altruistic and nonaltruistic agents it also studies the effect of fiscal policy on aggregate capital accumulation and on the welfare of both types of agents it shows that an increase in the relative number of nonaltruists is pareto improving in the steady state it also shows that the introduction of public debt or unfunded social security has no effect on the longrun equilibrium but implies a transfer of resources from the nonaltruistic to the altruistic agents finally it indicates that inheritance taxation hurts not only the altruists but also the nonaltruists

stability chaos and multiple attractors a single agent makes a difference abstract this paper provides an example in which a slight behavioral heterogeneity may fundamentally change the dynamical properties of a nonlinear cobweb market with a quadratic cost function and an isoelastic demand function we consider two types of producers cautious adapters and naive optimizers in a market of naive optimizers a single cautious adapter stabilizes the otherwise exploding market in a market of cautious adapters a single naive optimizer may destabilize the market without him there exists at most one periodic attractor in the market but with him there may appear many and even infinitely many coexisting periodic attractors

trading heterogeneity under information uncertainty abstract instead of heuristical heterogeneity assumption in the current heterogeneous agent models hams we derive the trading heterogeneity by introducing information uncertainty about the fundamental value to a ham conditional on their private information about the fundamental value agents choose different trading strategies when optimizing their expected utilities this provides a micro foundation to heterogeneity and switching behavior of agents we show that the ham with trading heterogeneity originating from the incomplete information performs equally well if not better than existing hams in generating bubbles crashes and mean reverting prices the simulated time series matches with the s p 500 in terms of power law distribution in returns volatility clustering and long memory in volatility

on the bimodality of the distribution of the s p 500 s distortion empirical evidence and theoretical explanations abstract after showing that the distribution of the s p 500 s distortion i e the log difference between its real stock market index and its real fundamental value is bimodal we demonstrate that agent based financial market models may explain this puzzling observation within these models speculators apply technical and fundamental analysis to predict asset prices since destabilizing technical trading dominates the market near the fundamental value asset prices tend to be either overvalued or undervalued interestingly the bimodality of the distribution of the s p 500 s distortion confirms an implicit prediction of a number of seminal agent based financial market models

fertility and childlessness in the united states we develop a theory of fertility distinguishing its intensive margin from its extensive margin the deep parameters are identified using facts from the 1990 us census i fertility of mothers decreases with education ii childlessness exhibits a u shaped relationship with education iii the relationship between marriage rates and education is hump shaped for women and increasing for men we estimate that 2 5 percent of women were childless because of poverty and 8 1 percent because of high opportunity cost of childrearing over time historical trends in total factor productivity and in education led to a u shaped response in childlessness rates while fertility of mothers decreased

nonlinear dynamics and stock returns simple deterministic systems are capable of generating chaotic output that mimics the output of stochastic systems for this reason algorithms have been developed to distinguish between these two alternatives these algorithms and related statistical tests are also useful in detecting the presence of nonlinear dependence in time series in this article the authors apply these procedures to stock returns and find evidence that indicates the presence of nonlinear dependence on weekly returns from the center for research in security prices value weighted index copyright 1989 by the university of chicago

exchange rate expectations of chartists and fundamentalists this paper provides novel evidence on exchange rate expectations of both chartists and fundamentalists separately these groups indeed form expectations differently chartists change their expectations more often however all professionals expectations vary considerably as they generally follow strong exchange rate trends in line with non linear exchange rate modeling professionals expect mean reversion only if exchange rates deviate much from ppp chartists survive in fx markets as they forecast equally accurately as fundamentalists unexpected from an effcient market viewpoint chartists even outperform fundamentalists at short horizons overall these findings clearly support the chartist fundamentalist approach

disequilibrium economic dynamics a post schumpeterian contribution abstract adaptive economizing in a decentralized economy with alternative technologies and scarce resources leads to various kinds of locally unstable behavior economic disequilibrium is the rule in such a world and requires the presence of market mechanisms that make possible continued viability if in addition to local instability economies are also globally unstable as considerable evidence suggests then the discovery and application of new structure is essential a complete dynamic theory of economic change must therefore be based not only on conventional rationality and routinely adapting behavior but on a superior faculty which may perhaps best be called creative intelligence

structural stochastic volatility in asset pricing dynamics estimation and model contest abstract in the framework of small scale agent based financial market models the paper starts out from the concept of structural stochastic volatility which derives from different noise levels in the demand of fundamentalists and chartists and the time varying market shares of the two groups it advances several different specifications of the endogenous switching between the trading strategies and then estimates these models by the method of simulated moments msms where the choice of the moments reflects the basic stylized facts of the daily returns of a stock market index in addition to the standard version of msm with a quadratic loss function we also take into account how often a great number of monte carlo simulation runs happen to yield moments that are all contained within their empirical confidence intervals the model contest along these lines reveals a strong role for a tamed herding component the quantitative performance of the winner model is so good that it may provide a standard for future research

an intergenerational model of population growth the problem of population growth has been only partially formulated in an intertemporal context therefore a link between population theory and economic growth theory is still missing this paper attempts to provide such a link by analyzing an intergenerational model of optimum population growth the model accommodates the idea that decisions on increases in population should consider the new population s quality of life this concept is elaborated upon in a static framework by gary becker and gregg lewis dennis de tray and robert willis other literature on population growth such as harold votey disregards this consideration altogether 2 more explicitly this paper assumes that the utility of each generation is a function of the level of its consumption and the number and utility of the newly born people we are thus led to consider the utility of an infinite number of generations this model differs from paul samuelson s intergenerational model of pure consumption in which the utility of each generation depends only on that generation s own consumption recently philip neher 1971 analyzed a model of fertility in primitive economies it is based on the assumption that parents use children as investments to insure future consumption needs neher s analysis focuses entirely on the pension motive for having children 3 our model assumes that fertility is determined so as to balance the parents welfare derived from additional children against that derived from the children s quality of life we first outline a general model of optimum population growth in order to discuss explicitly various economic aspects of population we use a simple case in the analysis section i sets up the basic model

speculative behaviour and complex asset price dynamics a global analysis this paper analyses the dynamics of a model of a share market consisting of two groups of traders fundamentalists who base their trading decisions on the expectation of a return to the fundamental value of the asset and chartists who base their trading decisions on an analysis of past price trends the model is reduced to a two dimensional map whose global dynamic behaviour is analysed in detail the dynamics are affected by parameters measuring the strength of fundamentalist demand and the speed with which chartists adjust their estimate of the trend to past price changes the parameter space is characterized according to the local stability instability of the equilibrium point as well as the non invertibility of the map the method of critical curves of non invertible maps is used to understand and describe the range of global bifurcations that can occur it is also shown how the knowledge of deterministic dynamics uncovered here can aid in understanding the behaviour of stochastic versions of the model

an analysis of the effect of noise in a heterogeneous agent financial market model abstract heterogeneous agent models hams in finance and economics are often characterised by high dimensional nonlinear stochastic differential or difference systems because of the complexity of the interaction between the nonlinearities and noise a commonly used often called indirect approach to the study of hams combines theoretical analysis of the underlying deterministic skeleton with numerical analysis of the stochastic model however it is well known that this indirect approach may not properly characterise the nature of the stochastic model this paper aims to tackle this issue by developing a direct and analytical approach to the analysis of a stochastic model of speculative price dynamics involving two types of agents fundamentalists and chartists and the market price equilibria of which can be characterised by the stationary measures of a stochastic dynamical system using the stochastic method of averaging and stochastic bifurcation theory we show that the stochastic model displays behaviour consistent with that of the underlying deterministic model when the time lag in the formation of price trends used by the chartists is far away from zero however when this lag approaches zero such consistency breaks down

can a stochastic cusp catastrophe model explain stock market crashes this paper is the first attempt to fit a stochastic cusp catastrophe model to stock market data we show that the cusp catastrophe model explains the crash of stock exchanges much better than other models using the data of u s stock markets we demonstrate that the crash of october 19 1987 may be better explained by cusp catastrophe theory which is not true for the crash of september 11 2001 with the help of sentiment measures such as the index put call options ratio and trading volume the former models the chartists the latter the fundamentalists we have found that the 1987 returns are bimodal and the cusp catastrophe model fits these data better than alternative models therefore we may say that the crash has been led by internal forces however the causes for the crash of 2001 are external which is also evident in much weaker presence of bifurcations in the data in this case alternative models explain the crash of stock exchanges better than the cusp catastrophe model

boom bust dynamics in a stock market participation model with heterogeneous traders abstract the boundedly rational heterogeneous agent literature can be considered to have properly started with a number of contributions in the early 90s with the impressive contribution by carl chiarella who amongst his huge field of research developed several milestone models of heterogeneous interacting agents that are able to generate a number of dynamic outcomes compatible with the empirical evidence in this paper we propose a stock market model in which participation depends upon an attractiveness measure related to the market activity and the fundamental value of the market a market maker adjusts the stock price with respect to the current endogenous excess market demand which in turn depends on the demands of the different types of agents populating the economy market participants are also allowed to switch between different strategies analytical and numerical results confirm how the participation mechanism amplifies the occurrence of endogenous booms and busts in line with empirical and experimental evidence

the bull and bear market model of huang and day some extensions and new results abstract we develop a financial market model with interacting chartists and fundamentalists that embeds the famous bull and bear market model of huang and day as a special case their model is given by a one dimensional continuous piecewise linear map our model on the other hand is more flexible and is represented by a one dimensional discontinuous piecewise linear map nevertheless we are able to provide a more or less complete analytical treatment of the model dynamics by characterizing its possible outcomes in parameter space in addition we show that quite different scenarios can trigger real world phenomena such as bull and bear market dynamics and excess volatility

heterogeneity in exchange rate expectations evidence on the chartist fundamentalist approach abstract this paper examines heterogeneity in exchange rate expectations whereas agents heterogeneity is key in modern exchange rate models evidence on determinants of heterogeneity is weak thus far our sample covering expectations from about 300 forecasters over 15 years shows remarkable time variation in dispersion determinants of dispersion are consistent with the chartist fundamentalist approach misalignments of the exchange rate and exchange rate changes explain heterogeneity the risk premium influences heterogeneity as well but possible impacts from macroeconomic variables and exchange rate s volatility are dominated by the other determinants

coordinated bubbles and crashes abstract in a market with information friction investors strategically consider the actions of others and evolutionarily switch between fundamental and technical strategies to maximize their payoffs the collective actions of all investors exert feedback on asset price which affects investors subsequent actions we find that investors have the incentive to adopt fundamental strategy to restore market efficiency only if the mispricing is sufficiently large when investors fail to coordinate on the fundamental strategy market inefficiency increases which blows the bubble as market inefficiency grows the coordination on fundamental strategy strengthens which eventually bursts the bubble

effects of tobin taxes in minority game markets we show that the introduction of tobin taxes in agent based models of currency markets can lead to a reduction of speculative trading and reduce the magnitude of exchange rate fluctuations at intermediate tax rates in this regime revenues for the market maker obtained from speculators are maximal we here focus on minority game models of markets which are accessible by exact techniques from statistical mechanics results are supported by computer simulations our findings suggest that at finite systems sizes the effect is most pronounced in a critical region around the phase transition of the infinite system but much weaker if the market is operating far from criticality and does not exhibit anomalous fluctuations

inflation expectations and macroeconomic dynamics the case of rational versus extrapolative expectations the motivation of this paper is to understand the effects of coupling a macroeconomic model of inflation rate dynamics relying on an aggregate expectation to a heterogeneous expectations framework a standard macroeconomic textbook model consisting of okun s law an expectations augmented phillips curve and an aggregate demand relation is extended to allow agents the possibility of selecting between different types of forecasting strategies to predict the future inflation rate rules that have produced low prediction errors in the recent past are favored by agents here we consider trend following and rational expectations using a mixture of analytical and numerical tools we investigate the model s dynamics and discuss the conditions under which the extended model leads to endogenous fluctuations in macroeconomic variables some preliminary results are offered for the case in which a taylor like monetary policy rule is included in the model jel classification c61 c62 e31 e32

innovation and diffusion of clean green technology can patent commons help abstract this paper explores the characteristics of 238 patents on 90 inventions contributed by major multinational innovators to the eco patent commons which provides royalty free access to third parties to patented innovations on green technologies we compare the pledged patents to other patents in the same technologies or held by the same multinationals to investigate the motives of the contributing firms as well as the potential for such commons to encourage innovation and diffusion of climate change related technologies we find pledged patents to protect environmentally friendly technologies and to be of similar value as the average patent in a pledging firm s patent portfolio but of lower value than other patents in their class our analysis of the impact of the patent commons on diffusion of patented technologies suggests that making patents accessible royalty free did not result in any significant increase in diffusion as measured by citing patents this study therefore indirectly provides evidence on the role of patents in the development and diffusion of green technologies

heterogeneous expectations and speculative behavior in a dynamic multi asset framework abstract this paper develops a dynamic model of a financial market where heterogeneous agents invest among multiple risky assets and a risk free asset under a market maker scenario particular attention is paid to the case of two risky assets and two agent types fundamentalists and trend chasers whose beliefs on both first and second moments of the conditional distribution of returns are based on past observations conditions for the stability of the fundamental equilibrium are established and the effect of the correlation between the risky assets is examined it turns out that investors anticipated correlation and dynamic portfolio diversification do not always have a stabilizing role but rather may act as a source of complexity in the financial market

speculative behavior and the dynamics of interacting stock markets abstract we develop a simple agent based financial market model in which heterogeneous speculators apply technical and fundamental analysis to trade in two different stock markets speculators strategy market selections are repeated at each time step and depend on predisposition effects herding behavior and market circumstances simulations reveal that our model is able to explain a number of nontrivial statistical properties of and between international stock markets including bubbles and crashes fat tailed return distributions volatility clustering persistent trading volume coevolving stock prices and cross correlated volatilities against this background our model may be deemed to have been validated

exchange rate dynamics central bank interventions and chaos control methods abstract we use a simple chartist fundamentalist model developed by day and huang to explore recent chaos control algorithms as potential candidates for central bank intervention rules we find that methods such as delayed feedback control ogy and constant feedback have in principle the potential to reduce exchange rate variability and deviations from fundamentals even in the presence of large dynamic noise

complex bubble persistence in closed end country funds abstract we seek to resolve the misspecified fundamental problem in speculative bubbles through examining the behavior of closed end country funds which possess well defined fundamentals based on their net asset values we study six funds during an episode when large premia emerged and subsequently disappeared we apply rescaled range and regime switching tests which reject the no bubble null hypothesis for these premia these results are placed in a complex bubble model framework interpretable according to the big player model

examining the effectiveness of price limits in an artificial stock market abstract this paper proposes an agent based framework to examine the effectiveness of price limits in an artificial stock market the market is composed of many boundedly rational and heterogeneous traders whose learning behavior is represented by a genetic programming algorithm we calibrate the model to replicate several stylized facts observed in real financial markets based on this environment the impacts of price limits are analyzed from the perspectives of volatility price distortion volume and welfare we find that the imposition of price limits possesses both positive and negative effects however compared with the market without price limits appropriate price limits help to reduce volatility and price distortion and increase the liquidity and welfare

on the complicated price dynamics of a simple one dimensional discontinuous financial market model with heterogeneous interacting traders abstract we develop a financial market model with heterogeneous interacting agents market makers adjust prices with respect to excess demand chartists believe in the persistence of bull and bear markets and fundamentalists bet on mean reversion moreover speculators trade asymmetrically in over and undervalued markets and while some of them determine the size of their orders via linear trading rules others always trade the same amount of assets the dynamics of our model is driven by a one dimensional discontinuous map despite the simplicity of our model analytical graphical and numerical analysis reveals a surprisingly rich set of interesting dynamical behaviors

macroeconomic and stock market interactions with endogenous aggregate sentiment dynamics abstract this paper studies the implications of heterogeneous capital gain expectations on output and asset prices we consider a disequilibrium macroeconomic model where agents expectations on future capital gains affect aggregate demand agents beliefs take two forms fundamentalist and chartist and the relative weight of the two types of agents is endogenously determined we show that there are two sources of instability arising from the interaction of the financial with the real part of the economy and from the heterogeneous opinion dynamics two main conclusions are derived on the one hand perhaps surprisingly the non linearity embedded in the opinion dynamics far from the steady state can play a stabilizing role by preventing the economy from moving towards an explosive path on the other hand however real financial interactions and sentiment dynamics do amplify exogenous shocks and tend to generate persistent fluctuations and the associated welfare losses we consider alternative policies to mitigate these effects

linkages in international stock markets evidence from a classification procedure in this article we propose a new approach to evaluate the predictable components in stock indices using a boosting based classification technique and we use this method to examine causality among the three main stock market indices in the world during periods of large positive and negative price changes the empirical evidence seems to indicate that the standard poors 500 index contains incremental information that is not present in either the ftse 100 index financial times stock exchange index or the nikkei 225 index and that could be used to enhance the predictability of the large positive and negative returns in the three main stock market indices in the world this in turn would suggest a causality relationship running from the standard poors 500 index to both the ftse 100 and the nikkei 225 indices

an analysis of the cobweb model with boundedly rational heterogeneous producers abstract this paper considers the traditional cobweb model with heterogenous risk averse producers whose supply functions involve their estimates of the conditional mean and variance of the future price the producers seek to learn these quantities by applying geometric decay processes gdp to past prices the heterogeneity manifests itself in the lag lengths and memory parameters applied to past prices as well as in risk aversion coefficients we find that each dimension of heterogeneity changes enriches the cobweb dynamics with respect to the case of homogeneous producers

can a stochastic cusp catastrophe model explain housing market crashes abstract like stock market prices housing prices often exhibit temporary booms and busts a possible explanation for the observed abrupt changes is offered by the stochastic catastrophe model this paper addresses the question whether the catastrophe model can describe and predict the dynamics of housing markets we fit a stochastic cusp catastrophe model to empirical housing market data for six oecd countries us jp uk nl se and be two different estimation approaches are considered cobb s method and euler discretization the analysis shows that while cobb s approach describes the long run stationary density better euler discretization is more tailored for time series as it provides better one step ahead predictions proceeding using the euler discretization method we discuss the dynamics of housing markets in terms of the multiple equilibria cusp catastrophe model by considering the long term interest rate as an exogenous variable we obtain new insights into the policy implications of interest rate levels in particular concerning the stability of housing markets

education and fertility evidence from a natural experiment declining fertility is often attributed to the increased education of women it is difficult to establish a causal link because both fertility and education have changed secularly in this paper we study the connection between fertility and education using educational reform as an instrument to control for selection our results indicate that increasing education leads to postponement of first births away from teenage motherhood and towards women having their first birth in their 20s as well as for a smaller group up to the age of 35 40 we find no evidence however that more education results in more women remaining childless or having fewer children

dynamics of moving average rules in a continuous time financial market model within a continuous time framework this paper proposes a stochastic heterogeneous agent model ham of flnancial markets with time delays to unify various moving average rules used in discrete time hams the time delay represents a memory length of a moving average rule in discrete time hams intuitive conditions for the stability of the fundamental price of the deterministic model in terms of agents behavior parameters and memory length are obtained it is found that an increase in memory length not only can destabilize the market price resulting in oscillatory market price characterized by a hopf bifurcation but also can stabilize an otherwise unstable market price leading to stability switching as the memory length increases numerical simulations show that the stochastic model is able to characterize long deviations of the market price from its fundamental price and excess volatility and generate most of the stylized facts observed in flnancial markets

survey evidence on diffusion of interest and information among investors abstract questionnaire surveys of institutional and individual investors were undertaken to learn about patterns of communications it was found that direct interpersonal communications are very important in investor decisions questions elicited what fraction of investors were unsystematic and allowed themselves to be influenced by word of mouth communications or other salient stimuli randomly sampled investors were studied as well as investors in stocks whose price had recently increased dramatically contagion or epidemic models of financial markets are proposed in which interest in individual stocks is spread by word of mouth the survey evidence is interpreted as supporting such models

the price dynamics of common trading strategies a deterministic trading strategy can be regarded as a signal processing element that uses external information and past prices as inputs and incorporates them into future prices this paper uses a market maker based method of price formation to study the price dynamics induced by several commonly used financial trading strategies showing how they amplify noise induce structure in prices and cause phenomena such as excess and clustered volatility

ergodic fluctuations in deterministic economic models abstract nonperiodic business fluctuations are shown to exist with positive measure generically and to behave like stationary stochastic processes in the standard dynamic macro model the implication is that so called chaotic fluctuations are probable for random initial conditions in a large class of recursive economies

fertility transitions along the extensive and intensive margins this paper examines the fertility transition through a new lens the extensive margin parents with high levels of children might substitute quality for quantity as the constraints on quality relax or those on quantity tighten however along the extensive margin the quantity quality trade off cannot operate at low levels of fertility we expect quality and quantity to be essential complements we apply these insights to a large school construction program in the american south during the early 20th century the rosenwald rural schools initiative we find that increased schooling opportunities lead to reductions in fertility among women with high fertility levels while at the same time inducing higher levels of fertility among women with low levels of fertility the magnitude of the fertility changes induced in the parent generation is however small compared to the changes in fertility induced by the rosenwald intervention among women that were themselves treated by the intervention the evidence from the rosenwald intervention therefore suggests that changes in female opportunity costs induced by increased educational attainment might be among the most important driving forces of the fertility transition

microfoundations for switching behavior in heterogeneous agent models an experiment we run a laboratory experiment to study how human subjects switch between several profitable alternatives framed as mutual funds in order to provide a microfoundation for so called heterogeneous agent models the participants in our experiment have to choose repeatedly between two three or four experimental funds the time series of fund returns are exogenously generated prior to the experiment and participants are paid for each period according to the return of the fund they choose for most cases participants decisions can be successfully described by a discrete choice switching model often applied in heterogeneous agent models provided that a predisposition toward one of the funds is included the estimated intensity of choice parameter of the discrete choice model depends on the structure of the fund returns in particular it increases with correlation between past and future returns this suggests human subjects do not myopically chase past returns but are more likely to do so when past returns are more predictive of future returns a feature that is absent in the standard heterogeneous agent models

financial crises and interacting heterogeneous agents in this paper we examine various types of financial crises and conjecture their underlying mechanisms using a deterministic heterogeneous agent model ham in a market maker framework forward looking investors update their price expectations according to psychological trading windows and cluster themselves strategically to optimize their expected profits the switches between trading strategies lead to price dynamics in market that subsequently move price up and down and in the extreme case cause financial crises the model suggests that both fundamentalists and chartists could potentially contribute to the financial crises