国际碳交易的经济学理论分析

二氧化碳等温室气体的过度排放造成的全球气温上升已经威胁到人类的生存和发展。对国际碳交易的内涵及经济学理论进行了分析,对深入理解、研究国际碳交易理论基础和实践经验具有非常现实的作用和意义。     

A game theory model of regulatory response to insider trading

We develop a model which can help in explaining the evolving regulatory regime around insider trading. We form a simple sequential game-theoretical model of insider trading transactions and, utilizing Monte Carlo simulation to determine equilibrium, we show that costly investigations and low penalties incentivize traders to engage in illegal transactions. While the model helps to explain stiffer action by regulatory bodies, the question remains as to whether the elevated penalty levels are sufficient to prevent further insider trading.     

Insider trading with product differentiation

This paper investigates the effect of product differentiation on the real and financial decisions of a publicly-owned firm, competing $\grave{a}$ la Cournot with another privately-owned firm. The results show that the degree of product differentiation affects the stock price coefficients (i.e. the market maker’s response to the real signal and to the total order flow signal) and the output of the publicly-owned firm. It also appears to have a detrimental effect on the manager’s profits and compensation scheme. The paper then proposes an extension of the benchmark model to incorporate Cournot and Stackelberg competition between two insiders in the financial market. The type of the financial competition adopted has also an effect on the results of the benchmark model that sometimes depend on the degree of product differentiation.     

Endogenous trading constraints with incomplete asset markets

This paper endogenizes the borrowing constraints on capital in a production economy with incomplete markets. We find that these limits get looser with income, a property that is consistent with US data on credit limits. The framework with endogenous limits is then used to study the effects of a revenue neutral tax reform that eliminates capital income taxes. Our results illustrate that it is very important to take into account the effects of tax policies on the limits. Throughout the transition, these effects can be big enough to change the overall conclusion about the desirability of a tax reform.     

Insider trading with public and shared information

We study the impact of public information and shared information on traders' trading behavior in the context of Kyle's (1985) speculative market. We suppose that there are four types of traders in our model: one insider, M outsiders, liquidity traders, and market makers. We explicitly describe the unique linear Nash equilibrium and find that public information harms the insider but benefits the outsiders and noise traders. Also, the market is more efficient because of the existence of public information.     

International emissions trading with endogenous allowance choices

This paper compares endogenous choices of tradable and non-tradable emission allowances by non-cooperative countries. I find that the cost savings of trading do not necessarily lead to less pollution. In particular, environmentally more concerned countries usually choose less allowances if these are tradable, but this may be offset by the choice of more allowances on the side of environmentally less concerned countries. Moreover, if the establishment of a trading system requires the unanimous approval of all countries, there may be no agreement on trading even if it were to lead to less pollution overall. Conversely, a trading system may find unanimous approval even if it induces more pollution.     

Emission trading in Europe with an exchange rate

This paper explores the analytical and empirical properties of a new method for emission trading according to a fixed exchange rate. The exchange rate is based on the ratios of the marginal costs of abatement in the optimal solution in order to account for the impact of the location of emission sources on the deposition. It is shown that, generally, this system will not achieve the optimal solution and does not guarantee that environmental deposition constraints are not violated, although total abatement costs are always reduced. A routine was developed to mimic trading as a bilateral, sequential process, subject to an exchange rate. In the example used, results for SO₂ emissions in Europe show that, starting from a uniform reduction, exchange-rate trading achieves higher cost savings than one-to-one trading, without achieving the cost minimum. Sulfur deposition targets are not violated since the initial emission allocation overfulfilled targets at many places. The results are sensitive to: pre-trade emission levels, the transaction costs, the availability of information on potential cost savings and assumptions made on the behavior of trading partners.     

Speculative trading with rational beliefs and endogenous uncertainty

Summary. This paper introduces the framework of rational beliefs of Kurz (1994), which makes the assumptions of heterogeneous beliefs of Harrison and Kreps (1978) and Morris (1996) more plausible. Agents hold diverse beliefs that are “rational” in the sense of being compatible with ample observed data. In a non-stationary environment the agents only learn about the stationary measure of observed data, but their beliefs can remain non-stationary and diverse. Speculative trading then stems from disagreements among traders. In a Markovian framework of dividends and beliefs, we obtain analytical results to show how the speculative premium depends on the extent of heterogeneity of beliefs. In addition, we demonstrate that there exists a unique Rational Belief Equilibrium (RBE) generically with endogenous uncertainty (as defined by Kurz and Wu, 1996) and that the RBE price is higher than the rational expectation equilibrium price (REE) under some general conditions Received: March 15, 2001; revised version: April 26, 2002 RID="*" ID="*" We are deeply grateful to Mordecai Kurz for his constant encouragement and inspiring guidance over the years. We wish to express our gratitude to an anonymous referee for the very valuable comments provided. We also thank Kenneth Arrow, Peter Hammond, Roko Aliprantis and Nicholas Yannelis for their helpful suggestions and Academia Sinica and the National Science Council of the R.O.C. for their indispensable support. Correspondence to: H.-M. Wu     

Two-period trading sentiment asset pricing model with information

We present a dynamic asset pricing model with investor sentiment and information, which shows that the investor sentiment plays a systematic and important role in the asset prices and the information is gradually incorporated into prices. The model has an analytical solution to the sentiment equilibrium price. We find that sentiment trading quantity not only increases the market liquidity, but also causes the asset prices' overreaction if the intensity of sentiment demand is more than a constant value. Therefore, the continuing overreactions result in a short-term momentum and a long-term reversal. The model could offer a partial explanation to some financial anomalies such as price bubbles, high volatility, asset prices' overreaction and so on.     

Asset price volatility and trading volume with rational beliefs

Summary. This paper develops a model of speculative trading in a large economy with a continuum of investors. In our model the investors are assumed to have diverse beliefs which are rational in the sense of being compatible with observed data. We demonstrate the existence of price amplification effects and show that the equilibrium prices can be higher or lower than the rational expectation equilibrium price. It is also shown that trading volume is positively related to the directions of price changes. Moreover, we study how asset price volatility and trading volume are influenced by belief structures, short selling constraints and the amount of fund available for investment.Received: 23 January 2003, Revised: 30 April 2003, JEL Classification Numbers: D84, G12.We are grateful to Professors Mordecai Kurz, Kenneth Arrow, Kenneth Judd, Carsten Nielsen, Maurizio Motolese, Mark Garmaise, Jean-Michel Grandmont, Peter Hammond, Karl Shell, Jan Werner and participants of the Society for the Advancement of Economic Theory (SAET) Conference and Stanford Institute of Theoretical Economics (SITE) Conference for many helpful suggestions. Correspondence to: H.-M. Wu     

Concurrent trading in two experimental markets with demand interdependence

Summary. We report results from fifteen computerized double auctions with concurrent trading of two commodities. In contrast to prior experimental markets, buyers' demands are induced via CES earnings functions defined over the two traded goods, with a fiat money expenditure constraint. Sellers receive independent marginal cost arrays for each commodity. Parameters for buyers' earnings functions and sellers' costs are set to yield a stable, competitive equilibrium. In spite of the complexity introduced by the demand interdependence, the competitive model is a good predictor of market outcomes, although prices tend to be above (below) the competitive prediction in the low-price (high-price) market.     

Alternative intertemporal permit trading regimes with stochastic abatement costs

We examine the social efficiency of alternative intertemporal permit trading regimes. The role of uncertainty and information asymmetry is discussed. For banking to be welfare improving, uncertainty itself does not matter, while information asymmetry does. Three effects of banking are identified: externality effect, information effect, and total permit effect. In the absence of total permit effect, banking is welfare improving if information effect is positive and dominates the externality effect. The relative efficiency of banking regimes with different intertemporal trading ratios is affected by the slope of the benefit and damage functions and the covariance of the shocks.     

The dynamics of efficient asset trading with heterogeneous beliefs

This paper analyzes the dynamic properties of portfolios that sustain dynamically complete markets equilibrium when agents have heterogeneous priors. We argue that the conventional wisdom that belief heterogeneity generates continuous trade and significant fluctuations in individual portfolios may be correct but it needs some qualifications. We consider an infinite horizon stochastic endowment economy populated by many Bayesian agents with heterogeneous priors over the stochastic process of the states of nature. Our approach hinges on studying the portfolios that decentralize Pareto optimal allocations. Since these allocations are typically history dependent, we propose a methodology to provide a complete recursive characterization when agents believe that the process of states of nature is i.i.d. but disagree about the probability of the states. We show that even though heterogeneous priors within that class can indeed generate genuine changes in the portfolios of any dynamically complete markets equilibrium, these changes vanish with probability one if the true process consists of i.i.d. draws from a common distribution and the support of some agent's prior belief contains the true distribution. Finally, we provide examples in which asset trading does not vanish because either (i) no agent learns the true conditional probability of the states or (ii) some agent does not know the true process generating the data is i.i.d.     

Real and financial effects of insider trading with correlated signals

Summary. In this paper we study the real and financial effects of insider trading in a Static, Kyle-type model. In our model the insider is also the manager of the firm. Hence the insider chooses both the amount of the real output to be produced and the amount of the stock of the firm to trade. The aim of the paper is to study the relationship between financial decisions and real decisions. In particular, we examine how insider trading on the stock market affects the real output and price and how the real decision making affects the financial variables, such as the extent of insider trading, stock prices, and the stock pricing rule of the market maker. In the model, the market maker observes two correlated signals: the total order flow and the market price of the real good. We study the informativeness of the stock price and the effects on insider's profits. We also construct a compensation scheme that aligns the interests of the insider and the firm. Finally, we generalize the pricing rule set up by a competitive market maker and analyze the comparative statics of the model. Received: October 3, 1999: revised version: December 1, 1999     

Endogenous market power in an emissions trading scheme with auctioning

This paper contributes to the literature on market power in emissions permits markets, modeling an emissions trading scheme in which polluters differ with respect to their marginal abatement costs at the business-as-usual emissions. The polluters play a two-stage static complete information game in which their market power arises endogenously from their characteristics. In the first stage all polluters bid in an auction for the distribution of the fixed supply of permits issued by the regulator, and in the second stage they trade these permits in a secondary market. For compliance, they can also engage in abatement activity at a quadratic cost. Under the assumptions of the model, in equilibrium all polluters are successful in the auction. In the secondary market the low-cost emitters are net sellers and the high-cost emitters are net buyers. Moreover, the high-cost emitters are worse off as a result of the strategic behavior. In addition, the secondary market price is unambiguously above the auction clearing price. I find that the aggregate compliance cost when polluters act strategically increases in the heterogeneity of their marginal abatement costs at the business-as-usual emissions, but there exists a threshold of the fixed supply of permits above which strategic behavior is compliance cost-saving for the polluters. Finally, for a low enough variance of the marginal abatement cost at the business-as-usual emissions, strategic behavior is compliance cost-saving for the polluters, regardless of the level of the available supply of permits.     

Vertical trading and uneven development

The phenomenon of vertical trading, in which the center exports a good involving a high degree of processing which leads to economy-wide learning and the periphery exports a good which does not generate such effects, is formalized in a simple dynamic model of trade. It is shown that the periphery can ‘lose’ from such trade relations. Conditions under which this can occur are shown to involve parameters of the learning functions, and the ‘sizes’ of the two countries.     

Insider trading and stock prices

We examine the informational content of insider trades and its value to market investors using a US dataset. Overall, our results support the view that insider actions have positive predictive power for future returns. However, these results may come with some caveats. First, it is not the actions of all insiders (directors, officers and large shareholders) that have predictive power for future returns, but typically only those of directors and officers (senior management). Second, while director actions have predictive power for firm of all sizes, officers only have predictive power for small firms. The signal emanating from buys is stronger than the signal emanating from sells. Finally, the trading actions of directors, and to a lesser extent, officers have significant effects on the trading behaviour of other groups of insiders.     

The relationship between top trading cycles mechanism and top trading cycles and chains mechanism

In this paper, we show that there is a relationship between two important matching mechanisms: the Top Trading Cycles mechanism (TTC mechanism proposed by Abdulkadiroglu and Sonmez, 1999) and the Top Trading Cycles and Chains mechanism (TTCC mechanism proposed by Roth, Sonmez, and Unver, 2004). Our main result is that when a specific chain selection rule proposed by Roth et al. is used, these two mechanisms are equivalent. While the equivalence is relevant for one specific case of the TTCC mechanism, it is a particularly interesting case since it is the only version identified by Roth et al. to be both Pareto-efficient and strategy-proof.     

Efficient mechanisms for bilateral trading

We consider bargaining problems between one buyer and one seller for a single object. The seller's valuation and the buyer's valuation for the object are assumed to be independent random variables, and each individual's valuation is unknown to the other. We characterize the set of allocation mechanisms that are Bayesian incentive compatible and individually rational, and show the general impossibility of ex post efficient mechanisms without outside subsidies. For a wide class of problems we show how to compute mechanisms that maximize expected total gains from trade, and mechanisms that can maximize a broker's expected profit.     

Softening competition through forward trading

In the history of alleged manipulations on forward markets, it has been observed that high prices resulted from a cartel's long positions. The present paper addresses this issue in a simple model of price setting duopolists. We show that forward trading results in producers buying forward their own production, so that equilibrium prices are increased compared to the case without forward trading. This result contrasts with the social desirability of forward markets emphasized by the academic literature.