Two-period model of insider trading with correlated signals

In this article, we extend the one-period model of Jain and Mirman (1999) for asset trading with two correlated signals to a two period model. We then prove the existence and uniqueness of the Bayesian linear equilibrium. Finally, we perform comparative statics analysis with respect to Kyle (1985). Our findings reveal that adding another correlated signal (the real signal) to the total order flow of Kyle (1985), increases the amount of information incorporated in the stock price at each period and decreases the insider’s expected profits at each period.     

Differentiated goods in a dynamic Cournot duopoly with emission charges on output

We extend the dynamic Cournot duopoly framework with emission charges on output by Mamada and Perrings (Econ Anal Policy 66:370–380, 2020), which encompassed homogeneous products in its original formulation, to the more general case of differentiated goods, in order to highlight the richness in its static and dynamic outcomes. Each firm is taxed proportionally to its own emission only and charge functions are quadratic. Moreover, due to an adjustment capacity constraint, firms partially modify their output level toward the best response. Like in Mamada and Perrings (Econ Anal Policy 66:370–380, 2020), the only steady state coincides with the Nash equilibrium, and it will be considered admissible when it guarantees the positivity of the marginal emission charge. We find that the full efficacy of the environmental policy, which applies to an equilibrium that is globally asymptotically stable anytime it is admissible, is achieved in the case of independent goods, as well as with a low good interdependence degree in absolute value, independently of being substitutes or complements. When goods are substitutes and their interdependence degree is high, the considered environmental policy is still able to reduce pollution at the equilibrium, but the latter is stable just when the policy intensity degree is large enough. When instead goods are complements and their interdependence degree is high in absolute value, the considered environmental policy produces detrimental effects on the pollution level and the unique equilibrium is always unstable, when admissible. This highlights that, from the static viewpoint, even in the absence of free riding possibilities, the choice of the mechanism to implement has to be carefully pondered, according to the features of the considered economy.

     

Robust games: theory and application to a Cournot duopoly model

In this paper, the robust game model proposed by Aghassi and Bertsimas (Math Program Ser B 107:231–273, 2006) for matrix games is extended to games with a broader class of payoff functions. This is a distribution-free model of incomplete information for finite games where players adopt a robust-optimization approach to contend with payoff uncertainty. They are called robust players and seek the maximum guaranteed payoff given the strategy of the others. Consistently with this decision criterion, a set of strategies is an equilibrium, robust-optimization equilibrium, if each player’s strategy is a best response to the other player’s strategies, under the worst-case scenarios. The aim of the paper is twofold. In the first part, we provide robust-optimization equilibrium’s existence result for a quite general class of games and we prove that it exists a suitable value \(\epsilon \) such that robust-optimization equilibria are a subset of \(\epsilon \)-Nash equilibria of the nominal version, i.e., without uncertainty, of the robust game. This provides a theoretical motivation for the robust approach, as it provides new insight and a rational agent motivation for \(\epsilon \)-Nash equilibrium. In the last part, we propose an application of the theory to a classical Cournot duopoly model which shows significant differences between the robust game and its nominal version.     

An equilibrium model of insider trading in continuous time

We study a Bayesian–Nash equilibrium model of insider trading in continuous time. The supply of the risky asset is assumed to be stochastic. This supply can be interpreted as noise from nonrational traders (noise traders). A rational informed investor (the insider) has private information on the growth rate of the dividend flow rewarded by the risky asset. She is risk averse and maximizes her inter-temporal utility rate over an infinite time-horizon. The market is cleared by a risk neutral market maker who sets the price of the risky asset competitively as the conditional present value of future dividends, given the information supplied by the dividend history and the cumulative order flow. Due to the presence of noise traders, the market demand does not fully reveal the insider’s private information, which slowly becomes incorporated in prices. An interesting result of the paper is that a nonstandard linear filtering procedure gives an a priori form for the equilibrium strategy to be postulated. We show the existence of a stationary linear equilibrium where the insider acts strategically by taking advantage of the camouflage provided by the noise which affects the market maker’s estimates on private information. In this equilibrium, we find that the insider’s returns on the stock are uncorrelated over long periods of time. Finally, we show that the instantaneous variance of the price under asymmetric information lies between the instantaneous variance of the price under complete and incomplete information. The converse inequalities hold true for the unconditional variance of the price.     

Quality-improving R&D and merger policy in a differentiated duopoly: Cournot and Bertrand equilibria

We combine a model of product research and development (R&D) and technological spillover with the concept of technological distance and examine horizontal mergers in a duopolistic market with R&D. The results are fourfold. First, a merger can better encourage R&D investment than the competition case. Second, with a small degree of product differentiation (PD), the merger criterion under the Cournot duopoly is stricter than that of the Bertrand case. By contrast, with a moderate or large degree of PD, the opposite is true. Third, with a small technological distance, a merger should be allowable. Finally, with a small degree of PD and moderate technological distance, a merger should be allowable.     

Why the law on insider trading should not be tightened

Patrick Evershed, who manages the Brown Shipley Smaller Companies Fund, attacks the proposed tightening of the law on insider trading in the Criminal Justice Bill, The changes proposed would penalise honest fund managers.     

Filtration enlargement-based time series forecast in view of insider trading

This survey reviews filtration enlargement models in view of insider trading. Although filtration enlargement aptly models insiders' informational advantage, the theoretical results have not attracted the attention of the empiricists, owing mainly to the lack of a bridge transforming the results to testable hypotheses, and/or the absence of econometrics method linking the hypotheses and the data. This survey provides a feasible avenue to estimate insider information and to detect trading from a relatively sophisticated theoretical model, where the dynamics of publicly available data (e.g., stock price) implies insider information before the information is completely digested. We complete the survey with an empirical illustration based on simulated data.     

Option introduction and insider trading in the NASDAQ/NMS equity market

This paper investigates and supports the hypothesis that insiders have an incentive to shift their informed trading activities when options initially are listed for a firm. Firm size is found to be related to the level of insider trading activity. There is a significant decrease in insider equity-market volume for the smallest third of firms, a significant increase in insider-equity market volume for the middle third of firms, and a significant decrease in insider equity-market volume for the largest third of firms. This supports the hypothesis of a difference in the degree of impact on equity volume upon option introduction based upon firm size. This research provides additional evidence of informed trading activities when option introduction, insider trading, and firm size are considered simultaneously.     

内部交易存货涉及减值情形的所得税抵销与调整

企业集团内部交易存货在内部购买方将其售出企业集团之前,如果该批存货发生减值,合并财务报表,一方面,因内部交易差价产生的暂时性差异要进行所得税调整;另一方面,因内部购买方按未实现内部交易利润多提减值,而在个别报表中多确认的递延所得税资产要进行抵销处理,文章对此进行了探讨。     

The effect of earnings forecast precision on firm value and insider trading under voluntary disclosure in Taiwan

Taiwan changed its earnings forecast policy from mandatory to voluntary disclosure in 2005. In this study, the inferences of voluntary earnings forecast are examined based on forecasts issued by listed firms. This study suspects that insiders have a temptation to strategically manipulate financial forecast information to influence markets and thus receive extra rents. Under the new earnings forecast disclosure policy, the number of disclosing firm decreases but the precision of earnings forecast increases. The empirical result from dynamic panel data evidences the forecast error of voluntary disclosure may negatively impact firm values. Furthermore, there is a positive relationship between insiders＇ trading profit and manipulation of earnings forecasts. As volatility in insider manipulation increases, it is difficult for the investors to predict the real intention of insiders, and insiders may achieve greater benefits from trading. This study also observes that many listed companies hold investor conferences to provide earnings guidance in Taiwan. The reason may be that investor conference is more flexible and has less forecast error cost than the formal financial forecast. This study provides important insights into earnings forecast policy in emerging markets. The competent authority should improve corporate governance and develop monitoring functions to abate forecast manipulation.     

The joint decision to manage earnings through discretionary accruals and asset sales around insider trading: Taiwan evidence

This study assesses the joint decision of multiple earnings–management tools around insider trading. The Taiwanese evidence indicates significantly higher magnitudes of both discretionary accruals and asset sales before insider selling. In addition, to investigate the endogenous relationship between discretionary accruals and asset sales, this study develops a set of simultaneous equations and includes the inverse Mill’s ratio as a regressor to account for firms that choose not to use asset sales. The results indicate a marginal complementary correlation between discretionary accruals and asset sales before insider selling. Further tests find this complementary correlation becomes stronger when accompanying abnormal insider selling. The findings support the view that insiders consider both tools jointly and adjust them as complements to meet their directional earnings management objective.     

Spatial duopoly with discriminatory pricing

The concept and existence of an equilibrium is established for profit maximizing competitors whose decisions involve choices of both delivered price schedules and firm locations. Each firm faces a production function; each is allowed to locate in the plane and to set discriminatory prices. Any transport cost function that is continuous in the firm location variable may be used. It is shown that the locations of the two firms are in equilibrium if each firm is minimizing social cost (i.e., the total cost to the firms of supplying the market with the good it demands is minimized) with respect to the opponent's fixed location.     

Cournot oligopoly models with time delays

In this paper a system of competing firms is considered in which adjustments of output are subject to delays. Under the Cournot strategy, stability of the oligopoly problem is considered. If each firm calculates its optimal output based on a knowledge of its own production at that time, and of its competitor's outputs at a previous time, stability is not affected by the information delays. However, if all the information available to each firm is subject to a delay, then stability is affected, and the likelihood of stability increases with decreasing delays.     

Cournot tatonnement and potentials

We study what topological assumptions should be added to the acyclicity of individual best response improvements in order to ensure the existence of a (pure strategy) Nash equilibrium in a strategic game, as well as the possibility to reach a Nash equilibrium in the limit of a best response improvement path.     

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.     

Efficient trading with restriction

In a classical paper by Cramton, Gibbons, and Klemperer (CGK) (Econometrica 55:615–632, 1987), it is shown that an efficient trading mechanism exists if traders’ initial endowments are not too asymmetric. In this paper, we extend the CGK model by assuming that traders are not allowed to consume more than a given amount (upper bound) of the good. In the CGK model, instead the only restriction is that no agent can consume more than the entire endowment in the economy. By varying this upper bound, we characterize the set of endowments (efficient region) in which efficient trading mechanisms exist in terms of this upper bound. We show that the efficient region becomes smaller when the upper bound decreases. On the other hand, when this upper bound becomes the entire endowment of the economy, we obtain the result in CGK as a special case.     

A differential game in a duopoly with instantaneous incentives

In this paper, we study a differential game in which two competing firms exploit a public renewable resource that is relevant from a landscape point of view. We consider a policy maker that provides an instantaneous incentive to the firms in order to prevent the resource exhaustion during the whole extraction period, which coincides with the harvesting license period. We compute an open-loop Nash equilibrium of the differential game, showing that it coincides with a linear feedback Nash equilibrium. Finally, we compute the value of the incentive that leads to the maximization of social welfare considering the incentive both as a pure transfer and as a cost.     

Efficient trading with nonlinear utility

In an environment in which agents have nonlinear utility and sufficiently asymmetric initial endowments, we show that efficient trading is achievable. This result is in contrast with Myerson and Satterthwaite (1983), which shows efficient trading is not possible if agents have linear utility and asymmetric initial endowments. Our result is also different from Cramton et al. (1987), in which they maintain the linear utility assumption as in Myerson and Satterthwaite but assume that traders’ initial endowments are relatively symmetric.