A model of currency crises with heterogeneous market beliefs

This paper shows that the approach followed by Tamborini (2015) in analyzing and interpreting the euro area public debt crisis, based on the role played by agents characterized by heterogeneous market beliefs, can be applied also to the case of currency crises. By doing so, rather than considering the private sector as an atomistic player endowed with perfect information, and by considering a central bank that optimizes the amount of unsterilized inflow of foreign reserves in a Mundell-Fleming type speculative attack model, allows to explain the interest rates convex non-linearity that characterized, for example, a country like Italy during the 1992–93 EMS crisis.     

A continuous-time heterogeneous duopoly model with delays

In this paper, the continuous-time version with delays of the model of Tramontana (Econ Model 27(1):350–357, 2010) is presented. The stability of the equilibrium point is discussed by analyzing the distribution of roots of associated characteristic equation. It is found that combining marginal costs with time delays gives rise to different economic scenarios, where stability switches may appear and Hopf bifurcations occur within certain range of parameters.     

Adverse effects of leverage and short-selling constraints in a financial market model with heterogeneous agents

This paper investigates the impact of leverage and short-selling constraints on financial market stability. Investors׳ demand is modelled in a well-known asset pricing model with heterogeneous beliefs. In particular, I generalise the heterogeneous agents model of Brock and Hommes (1998) and Anufriev and Tuinstra (2013) to allow for leverage constraints as well as a short-selling tax. I consider two examples of adaptive belief systems describing the coevolution of prices and investors׳ beliefs. First, if the market is inhabited by fundamentalist and chartist traders, demand constraints have potential adverse effects and may restrict the stabilising fundamentalist strategy such that mispricing and price volatility increase. Second, if the market is inhabited by fundamentalists, optimists and pessimists with fixed beliefs, demand constraints drive down price volatility, but mispricing remains. The results suggest the stabilising effects of demand constraints in financial markets are limited. Only if asset prices are too high compared to fundamentals, policy makers should consider constraining leverage ratios in order to deflate financial bubbles.     

An analysis of the effect of noise in a heterogeneous agent financial market model

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.     

A pragmatic decision model for inventory management with heterogeneous suppliers

For enterprises, it is imperative that the trade-off between the cost of inventory and risk implications is managed in the most efficient manner. To explore this, we use the common example of a wholesaler operating in an environment where suppliers demonstrate heterogeneous reliability. The wholesaler has partial orders with dual suppliers and uses lateral transshipments. While supplier reliability is a key concern in inventory management, reliable suppliers are more expensive and investment in strategic approaches that improve supplier performance carries a high cost. Here we consider the operational strategy of dual sourcing with reliable and unreliable suppliers and model the total inventory cost where the likely scenario lead-time of the unreliable suppliers extends beyond the scheduling period. We then develop a Customized Integer Programming Optimization Model to determine the optimum size of partial orders with multiple suppliers. In addition to the objective of total cost optimization, this study takes into account the volatility of the cost associated with the uncertainty of an inventory system.     

Modelling market fundamentals: A model of the aluminium market

The standard approach to modelling primary commodity markets under rational expectations is to relate the commodity price to the production and consumption ‘surprises’ (i.e. the innovations on the equations). Using the world aluminium market, we show how this approach can be modified so that both the price and stock can be written in terms of one or more market ‘fundamentals’ which reflect the supply—demand balance on the market. This approach allows joint estimation of production, consumption, stock demand and price equations subject to cross-equation restrictions. It may be seen as a formalization of the approach adopted by metals industry analysts.     

Frankfurt Artificial Stock Market: a microscopic stock market model with heterogeneous interacting agents in small-world communication networks

We study the relationship between communication network topologies, namely the small-world networks introduced by Watts and Strogatz, and the simulation results of an artificial stock market, here the Frankfurt Artificial Stock Market. Heterogeneous interacting agents communicate their success and trading strategy to their nearest neighbors. A process of information diffusion arises through the adaptive behavior of agents when encountering more successful strategies in their direct neighborhood. We will show that an increasing rewiring probability of the small-world network will lead to higher volatility and distortion within our simulation model. It seems probable that the spatial position of traders within a communication network affects the price building process.     

A heterogeneous agent model of asset price dynamics with two time delays

This study constructs a heterogeneous agents model of a financial market in a continuous-time framework. There are two types of agents, fundamentalists and chartists. The former follows the traditional efficiency market theory and has a linear demand function, whereas the latter experiences delays in the formation of price trends and possesses a S-shaped demand function. The main feature of this study is a theoretical investigation on the effects caused by two time delays in a price adjustment process. In particular, two main results are demonstrated: One is that the stability switching curves are analytically derived, and the other is that the stability losses and gains can repeatedly occur when the shape of the curves are meandering. Although it is well known that a time delay has a destabilizing effect, these results imply that multiple delays can stabilize and destabilize a market price generating persistent deviations from the stationary price.     

A model for dual health care market with congestion differentiation

The French market for specialist physician care has a dual legal structure: physicians must exclusively work in sector 1 and charge regulated fees or in sector 2, where they can freely set their fees. Patient out-of-pocket payments in sector 2 are partially covered by private insurance. The primary differentiating factor between both sectors is the number of patients per specialist, which in turn directly affects the overall quality of the service provided. We built an equilibrium model to analyze both specialists' decisions about which sector to work in, and patients' choice of physician and therefore sector. More specifically, the model allowed us to study the effect of changes in prices and economy-wide patient-to-specialist ratios on profits and patients' utility associated with the services provided in each sector.     

Asset price and wealth dynamics in a financial market with heterogeneous agents

This paper considers a discrete-time model of a financial market with one risky asset and one risk-free asset, where the asset price and wealth dynamics are determined by the interaction of two groups of agents, fundamentalists and chartists. In each period each group allocates its wealth between the risky asset and the safe asset according to myopic expected utility maximization, but the two groups have heterogeneous beliefs about the price change over the next period: the chartists are trend extrapolators, while the fundamentalists expect that the price will return to the fundamental. We assume that investors’ optimal demand for the risky asset depends on wealth, as a result of CRRA utility. A market maker is assumed to adjust the market price at the end of each trading period, based on excess demand and on changes of the underlying reference price. The model results in a nonlinear discrete-time dynamical system, with growing price and wealth processes, but it is reduced to a stationary system in terms of asset returns and wealth shares of the two groups. It is shown that the long-run market dynamics are highly dependent on the parameters which characterize agents’ behaviour as well as on the initial condition. Moreover, for wide ranges of the parameters a (locally) stable fundamental steady state coexists with a stable ‘non-fundamental’ steady state, or with a stable closed orbit, where only chartists survive in the long run: such cases require the numerical and graphical investigation of the basins of attraction. Other dynamic scenarios include periodic orbits and more complex attractors, where in general both types of agents survive in the long run, with time-varying wealth fractions.     

A computable market equilibrium model with markets for transferable discharge permits

This paper presents a mathematical programming model for numerically analyzing the impacts of a transferable discharge permit (TDP) system on resource allocation and the distribution of income in a competitive equilibrium setting. Key assumptions of the model are linear household commodity demands, Leontief production functions requiring both primary and produced factors, fixed primary factor supplies and linear pollution dispersion processes. A basic model is presented with discussion of how it may be modified to examine alternative TDP configurations. In addition, there is also a discussion of relationships between key primal and dual variables and of issues involved in actual numerical implementation of the model.     

A linear programming model of housing market equilibrium

This paper reviews Wheaton's assertion that the Herbert-Stevens Linear Programming Model produces solutions which do not meet Alonso's criteria for market equilibrium. It demonstrates that, although Wheaton's criticism is valid in general, under certain conditions an alternative specification of the objective function coefficients and the dual variables in the linear program produces a model whose solutions satisfy Alonso's criteria. Finally, this paper shows that the NBER model is an application in which a linear programming problem computes market equilibria.     

Tradability,closeness to market prices,and expected profit: their measurement for a binomial model of options pricing in a heterogeneous market

A reliable method of options pricing in real time would help various players, including hedgers and speculators, to make informed decisions. In this study, we develop an extensive simulation with multiple business environments, which includes the use of real data from the S&P 500 Index between the years 2010–2017 for the 30 days prior to expiration of the options. Forecasted tradability is computed based on the SH model: a theoretical model of real-time options pricing that takes into account players’ heterogeneity with regard to their willingness to accept offers proposed by the opposing player. The quality of the model is examined for the scenario in which the model players are speculators who act against the real market prices. We show that the equilibrium prices predicted by the SH model are close to the market prices (a deviation of up to approx. 3%) in an In-The-Money environment. Additionally, the tougher the players (i.e., the greater their level of unwillingness to accept a bid from the opposing player), the higher the average tradability. We also find that the level of willingness of the players has a greater effect on tradability than does option moneyness or the market trend.

     

BP构造在中国市场的新版图

虽然全球第二大石油巨头——英国石油公司(BP)在2006年新年来临之前无奈地关闭了自己在尼日利亚的两处油田,并且还与埃克森-美孚一起遭遇到了美国当局的反垄断诉讼,但在中国市场,BP却如鱼得水,其布局正一步步得以实现。     

Equilibria,stability and asymptotic dominance in a speculative market with heterogeneous traders

We consider a pure exchange economy where one risky and one riskless security are traded in discrete time. Individual demands are expressed as fractions of individual wealth and depend on traders’ forecasts about future price movement.Introducing the ‘Equilibrium Market Line’ as the locus of all possible equilibrium returns, we show that, irrespectively of the number of traders and of their investment behavior, the economy possesses isolated equilibria where a single agent dominates the market and continuous manifolds of equilibria where many agents hold finite wealth shares. Moreover, we prove that no global dominance order relation among strategies can be defined.     

Cross-border mergers and acquisitions with heterogeneous firms: Technology vs. market motives

The most common form of foreign direct investment (FDI) is cross-border mergers and acquisitions (M&A). A common explanation for M&A activity identified in the industrial organization literature is that firms seek technological expertise. However, this has not been examined in the FDI literature. In this paper, I develop and estimate a model of cross-border M&A and focus on the technology seeking explanation. In particular, I develop a general equilibrium model of exporting, greenfield FDI, technology-seeking cross-border M&A, and market-seeking cross-border M&A with heterogeneous firms. The model predicts that firms from a larger country are more likely to acquire in a smaller country when M&A activity is driven by a technology-seeking motive, but the opposite is true when it is driven by a market-seeking motive. Using detailed data on worldwide M&A activity from 1985 to 2007, I find empirical evidence that cross-border M&A activity exhibits behavior consistent with this prediction.     

Prediction market prices under risk aversion and heterogeneous beliefs

In this paper, we examine the properties of prediction market prices when risk averse traders have heterogeneous beliefs in state probabilities. We show that the equilibrium state prices equal the mean beliefs of traders about that state if and only if the traders’ common utility function is logarithmic. We also provide a necessary and sufficient condition ensuring that the state prices are systematically below or above the mean beliefs of traders, thus providing a rational explanation to the favorite-longshot bias in prediction markets.     

Behavior of the firm in a market for heterogeneous labor

This paper develops a dynamic model of the firm in a labor market where workers and jobs are heterogeneous with respect to skill. The firm's recruitment policy, in a heterogeneous market, consists of both a wage offer and a skill requirement. The explicit derivation of this policy serves to clarify the difference between the long-run and short-run relationship between wages and skills. The short-run shift in this relationship helps to explain the occupational upgrading that occurs in cyclical upswings. The model also highlights the impact of the skill level distribution on the rate of change of firms' wage offers.     

A commodity hierarchy model of the rental housing market

This paper presents and analyzes a theoretical model of the rental housing market which addresses the durable-good nature and the heterogeneous nature of housing, while focusing on the quality distribution of housing units. Units of different qualities are viewed as distinct substitute commodities. New construction rates, deterioration rates, rental prices, and stocks are considered to be endogenous. Equilibrium concepts are introduced; both the long-run and short-run equilibria are shown to exist and to be unique. Comparative static results are established. The model's utility is demonstrated by its application to the analysis of several housing market programs.