Intertemporal coordination in two-period markets

This paper studies the stability of the intertemporal coordination dynamics when the common knowledge of individual expectations of future prices is perturbed in a neighborhood of a perfect foresight equilibrium. The main forces that affect stability are: (i) the effect of a change in asset demand on second period spot market prices, and (ii) the effect on asset demand of a small change in second period prices. In an intertemporal market game whose interior Markov perfect equilibria correspond to perfect foresight equilibria, it is shown that though M-rationalizability implies the stability of the intertemporal dynamics, the converse is not always true.     

Evolution and market behavior with endogenous investment rules

In a repeated market for short-lived assets, we investigate wealth-driven selection among investment rules that depend on endogenous market variables, such as current and past prices. We study the random dynamical system describing prices and wealth dynamics and characterize local stability of the long-run equilibria in which one or a group of traders dominate. Multiplicity of stable and unstable equilibria, leading to path dependency and persistent heterogeneity, turns out to be a common phenomenon generated by two different mechanisms. Firstly, conditioning investment decisions on endogenous market variables implies that the relative performance of investment rules, in terms of average growth rates, may be different for different prevailing prices, so that the market may fail to select a global winner. Secondly, the feedback existing between past asset prices and current investment decisions can lead to a form of deterministic overshooting.     

Dividend paying assets,the unit root property,and suboptimality

We consider the stationary equilibria of one good overlapping generations (OLG) economies with a sequence of possibly incomplete asset markets and prove two results. First, we show that if some asset always pays a nonnegative dividend, then its price changes sign across states if and only if the Perron root of every agent’s matrix of intertemporal rates of substitution exceeds one. Second, we provide sufficient conditions in terms of dividends and asset prices such that, keeping asset prices fixed, a conditionally Pareto improving allocation is induced by a stationary reassignment of a single asset. When taken together the results show that when for some agent the Perron root exceeds one, the existence of an asset that pays a strictly positive dividend in every state is sufficient to induce an improvement.     

Cournot outcomes under Bertrand–Edgeworth competition with demand uncertainty

We provide new results for two-stage games in which firms make capacity investments when demand is uncertain, then, when demand is realized, compete in prices. We consider games with demand rationing schemes ranging from efficient to proportional rationing. In all cases, there is a subgame perfect equilibrium outcome coinciding with the outcome of the Cournot game with demand uncertainty if and only if (i) the fluctuation in absolute market size is small relative to the cost of capacity, or (ii) uncertainty is such that with high probability the market demand is very large and with the remaining probability the market demand is extremely small. Otherwise, equilibria involve mixed strategies. Further, we show under efficient rationing that condition (i) is sufficient for the unique equilibrium outcome to be an equilibrium outcome of the Cournot game with demand uncertainty.     

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.     

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.     

The saving,human wealth and asset pricing nexus: Evidence from around the world

The present study examines the dynamics of the saving, human wealth and asset pricing nexus across developed and emerging economies. We introduce two equilibrium asset pricing models in an intertemporal capital asset pricing framework, including the priced factors human wealth and market portfolio in the first framework and the saving and market portfolio in the second framework. Both asset pricing frameworks consist of two-factor, four-factor and five-factor asset pricing models. We control for size and value factors in the four-factor model and size, value and momentum factors in the five-factor model. The IV-GMM estimation and GRS test results indicate that human wealth and market portfolio for the first framework and saving and market portfolio in the second framework are primary priced factors in explaining the average returns for developed economies and the aggregate level. On the contrary, both frameworks fail to yield significant results explaining the average returns for emerging economies.     

Market selection of constant proportions investment strategies in continuous time

This paper studies the wealth dynamics of investors holding self-financing portfolios in a continuous-time model of a financial market. Asset prices are endogenously determined by market clearing. We derive results on the asymptotic dynamics of the wealth distribution and asset prices for constant proportions investment strategies. This study is the first step towards a theory of continuous-time asset pricing that combines concepts from mathematical finance and economics by drawing on evolutionary ideas.     

Constrained suboptimality when prices are non-competitive

The paper addresses the following question: how efficient is the market system in allocating resources if trade takes place at prices that are not competitive? Even though there are many partial answers to this question, an answer that stands comparison to the rigor by which the first and second welfare theorems are derived is lacking. We first prove a “Folk Theorem” on the generic suboptimality of equilibria at non-competitive prices. The more interesting problem is whether equilibria are constrained optimal, i.e. efficient relative to all allocations that are consistent with prices at which trade takes place. We discuss an optimality notion due to Bénassy, and argue that this notion admits no general conclusions. We then turn to the notion of p-optimality and give a necessary condition, called the separating property, for constrained optimality: each constrained household should be constrained in each constrained market. If the number of commodities is less than or equal to two, the case usually treated in the textbook, then this necessary condition is also sufficient. In that case equilibria are constrained optimal. When there are three or more commodities, two or more constrained households, and two or more constrained markets, this necessary condition is typically not sufficient and equilibria are generically constrained suboptimal.     

A dynamic CAPM with supply effect: Theory and empirical results

Breeden [Breeden, D. T. (1979). An intertemporal asset pricing model with stochastic consumption and investment opportunities. Journal of Financial Economics 7, 265–196] and Grinols [Grinols, E. L. (1984). Production and risk leveling in the intertemporal capital asset pricing model. The Journal of Finance 39, 5, 1571–1595] and Cox et al. [Cox, J. C., Ingersoll, J. E., Jr., & Ross, S. A. (1985). An intertemporal general equilibrium model of asset prices. Econometrica 53, 363–384] have described the importance of supply side for the capital asset pricing. Black [Black, S. W. (1976). Rational response to shocks in a dynamic model of capital asset pricing. American Economic Review 66, 767–779] derives a dynamic, multiperiod CAPM, integrating endogenous demand and supply. However, Black's theoretically elegant model has never been empirically tested for its implications in dynamic asset pricing. We first theoretically extend Black's CAPM. Then we use price, dividend per share and earnings per share to test the existence of supply effect with U.S. equity data. We find the supply effect is important in U.S. domestic stock markets. This finding holds as we break the companies listed in the S&P 500 into ten portfolios by different level of payout ratio. It also holds consistently if we use individual stock data.     

The empirical determination of technology and expectations: A simplified procedure

This paper makes three principal contributions to the growing body of empirically oriented research on dynamic factor demand systems that are based on the adjustment cost model of the firm. First, a simplified procedure is described for deriving demand and supply functions which are amenable to empirical estimation and which are consistent with intertemporal expected profit maximization and a general expectations formation process for future prices. Second, it is pointed out that estimation of a complete system of demand and supply functions permits the empirical identification of both the firm's technology and its expectations formation process. Finally, the procedure is applied to aggregate annual U.S. manufacturing data for the 1947-1977 period and the consistency of the data with the theoretical framework is investigated.     

Equilibrium in a mixed economy of arrow-debreu type

The functioning of the current NIS economies is severely affected by regulatory interferencies with supply and demand for many commodities. In particular, the presence of dual markets is characteristic for these economies. On the first market, typically the “low-price sector” of the economy, prices are fixed and the allocation of goods is determined by rationing schemes and governmental orders. On the second market, flexible prices resulting from the market mechanism coordinate demand and supply. It is allowed that any surplus of good purchased on the first market can be sold on the second market at the then prevailing market prices.     

Spatial market equilibria with flow-dependent supply and demand: The single commodity case

Existence and uniqueness of spatial price equilibria are analyzed for a single commodity market network in which supply and demand levels are allowed to depend on commodity flows as well as market prices. This framework makes possible the explicit incorporation of flow-dependent shipment costs into market supply and demand functions. Moreover, since many quantity signals are also expressible as flow-dependent variables, it is possible to incorporate a number of recent models of supply and demand behavior which allow for quantity signals as well as price signals. In this context, the main result of the paper is to establish the existence of spatial price equilibria for such market networks under quite general conditions. In addition, certain uniqueness results are established for the case of arc-generated networks.     

Wage premia and skill upgrading in Italy: why didn't the hound bark?

This paper presents firm-level evidence on the change of the employment share and the wage premium of non-manual workers in Italian manufacturing during the nineties. We find that the relative stability of the aggregate wage premium and employment share hides offsetting disaggregate forces: technical progress raises the relative demand for skilled labor within firms, whereas demand changes associated with trade reduce the relative demand for skills. Moreover, it is within the class of non-manual workers that most of the action takes place: the wage premium and employment share of executives rise substantially, while those of clerks fall in a similar proportion. Finally, we find that the export status of firms plays a key role in explaining labor market dynamics: exporters account for most of both demand-related and technology-related shifts. Overall, our results for Italy question the conventional view that the labor market is “rigid” due to labor market institutions.     

Financial markets with volatility uncertainty

We investigate financial markets under model risk caused by uncertain volatilities. To this end, we consider a financial market that features volatility uncertainty. We use the notion of G-expectation and its corresponding G-Brownian motion recently introduced by Peng (2007) to ensure a mathematically consistent framework. Our financial market consists of a riskless asset and a risky stock with price process modeled by geometric G-Brownian motion. We adapt the notion of arbitrage to this more complex situation, and consider stock price dynamics which exclude arbitrage opportunities. Volatility uncertainty results in an incomplete market. We establish the interval of no-arbitrage prices for general European contingent claims, and deduce explicit results in the Markovian case.     

On pure-strategy Nash equilibria in price–quantity games

This paper examines the existence and characteristics of pure-strategy Nash equilibria in oligopoly models in which firms simultaneously set prices and quantities. Existence of a pure-strategy equilibrium is proved for a class of price–quantity games. If the demand function is continuous, then the equilibrium outcome is similar to that of a price-only model. With discontinuous demand and limited spillover, there are rationing equilibria in which combined production falls short of market demand. Moreover, there might again be an equilibrium reflecting the outcome of a price game. Competition in price and quantity thus yields Bertrand outcomes under a variety of market conditions.     

Endogenous participation risk in speculative markets

This paper analyses the dynamic implications of an asset-pricing model with incomplete participation due to entry costs. It is shown that heterogeneity in entry costs can lead to the existence of multiple stochastic sunspot equilibria, whereby the number of agents in the market and asset prices fluctuate endogeneously over time in the absence of fundamental uncertainty. Such asset-price fluctuations occur despite the uniqueness of the deterministic equilibrium, and thus bear no link to the usual notion of steady-state indeterminacy. In addition to excess volatility, the equilibria exhibit predictable and conditionally heteroskedastic returns.     

Can a stochastic cusp catastrophe model explain housing market crashes?

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.     

Monetary reaction functions in a small open economy

Monetary reaction functions are constructed in an intertemporal optimization framework. The time-varying coefficients to be put on the variations of the exchange rate and the asset stock are then derived by solving a matrix Riccati equation. As the planning horizon extends to infinity, a related algebraic Riccati equation coincides with those derived from minimization of stationary state variances only under certain conditions. Under the assumed full information by the government, reaction functions using realized values of exogenous shocks result in dynamics that do not enjoy the same stability property as the ones obtained by explicit intertemporal optimization.     

Smooth preferences and the regularity of equilibria

To study equilibria we describe an economy by its distribution of consumers' preferences and endowments. All preferences are smooth and weakly convex. Demand of an economy need not be single valued, but there is an open dense set of economies for which demand is a C¹-function in a neighborhood of the equilibrium prices. We call an economy regular if its excess demand is transversal to zero. A regular economy has locally unique equilibria. It is shown that regular economies form an open dense set on which the equilibrium price correspondence varies continuously and the number of equilibria is locally constant.