看法差异、信息不对称、卖空限制与价格形成

本文构建了一个有卖空限制的指令驱动的市场交易模型，在模型中考虑了交易者之间的信息不对称和看法差异，应用博弈均衡的分析方法，求解模型的均衡结果。通过对均衡结果的分析表明：市场均衡是知情与未知情者之间的一个混同均衡，均衡报价是未知情买卖者之间分配交易剩余的结果，其分配依据是买卖双方各自不能实现交易的相对风险。市场均衡时，一定存在正的买卖价差，价差由限价指令的执行风险补偿项和逆向选择风险补偿项构成。执行风险补偿项是资产分散度指标的减函数，是知情者比例的增函数，并且随交易者看法分散程度的提高而增大。逆向选择风险补偿项是资产分散度指标和知情者比例的增函数，并且随着未知情者对信息掌握程度的提高而减小。     

国外股市内幕交易研究综述

股市内幕交易是国外金融市场理论的热点研究领域.国外内幕交易研究可以分为两个阶段.在初始阶段,研究尚停留在经验水平;20世纪80年代中后期以来,内幕交易研究基本进入成熟阶段.这一阶段的研究以噪音理性预期均衡模型为研究工具,对内幕交易进行了较为全面的分析.同时,内幕交易对内部交易人、外部交易者和上市公司也有着复杂的影响.     

考虑有限关注的多个信息交易者竞争交易分析

文章假设在一个具有唯一风险资产的金融市场中，存在多个风险中性的信息交易者、很多噪音交易者、风险中性的做市商三类交易者，其中信息交易者是有限关注的，他们通过权衡关注和竞争两种因素选择交易量。文章首先建立了信息交易者具有不同关注度的一般模型，然后建立了具有相同关注度的模型，通过求解唯一线性均衡，推导它的均衡特征，得出结论：信息交易者的交易强度、期望收益随着其他信息交易者关注度和信息交易者数量的增大而降低，随着自身的关注度的增大而增大；信息交易者数量较少时，期望收益随着信息交易者关注度的增大而增大；而信息交易者数量较多时，期望收益随着信息交易者关注度的增大起初快速增大，然后缓慢降低。     

知情交易的识别与测度的文献综述

知情交易是指由于市场中存在着非对称信息，一部分交易者利用自己所掌握的私有信息所进行的交易，对于知情交易的识别和测度已成为一个热门问题。本文从买卖价差，序贯交易模型，成交量，超常收益四个方面对已有的知情交易的识别和测度的文献进行了分类和总结。     

证券市场理性预期与泡沫的试验检验

理性预期理论认为在信息完全对称的条件下 ,理性投资者能够形成一致的预期 ,证券价格将处于均衡状态。本文借鉴Smith等 ( 1 988)、Sheryl和Holt( 1 998)的实验程序 ,构造了一个信息完全对称的实验室证券市场 ,选取在校学生、金融从业人员以及公务员等具有不同职业背景的参与人作为交易者 ,利用来自中国的实验数据对理性预期理论的有效性进行了检验。实验结果与国外现有研究基本一致 ,即在信息完全对称的实验环境下均出现了价格泡沫现象 ,直到交易过程的最后几个阶段市场价格才逐步收敛于理性预期的均衡价格 ;有经验的交易者组成的市场所产生的泡沫程度显著地少于没有经验的交易者。通过对不同职业背景的参与人实验结果进行比较 ,本文进一步认为经验的积累可能来源于两个途径 :一是通过重复实验积累的经验 ,二是通过实际证券交易经历形成的经验     

证券市场信息反馈理论浅析

本文借助Glosten/Milgrom(1985)的信息模型来分析在证券市场存在非对称信息的情况下,做市商为避免在和知情交易者进行交易时由于信息的不完整性时产生损失,而确立一个股票买卖价格的差额。做市商通过观察交易者的交易委托类型,借助贝叶斯定理来学习信息的反馈,而股票的真正价值会随着交易过程的延续最终体现在股票的价格中。该模型的研究为我国做市商制度的发展和完善提供了必要的理论依据。     

中国股市自相关性与反馈交易行为实证研究

本文通过对股市内不同类型交易者的行为进行分析,利用Watanabe(2002)的模型,对中国股市交易者的反馈交易行为进行了实证检验.结果表明:股市的波动率与自相关性之间具有反向的变动关系;股市收益在价格下降时,比价格上升时更具有负自相关性;股市中存在着正反馈交易行为,而且波动率越大,正反馈交易越显著.     

参与知情交易提高了基金业绩吗？

本文研究中国股市知情交易概率（probability of informedtrading,PIN,）与基金投资业绩之间的关系,采用Easleyeta1．（1996）提出的删测度,并进一步利用基金投资组合的PIN均值作为基金的信息测度。研究发现,知情交易概率与基金业绩之间存在显著的负相关关系。这说明对于基金而言,参与那些具有更高内幕／知情交易的股票,并没有取得更高的收益,或者即使本身作为知情交易者,基金根据所了解的私有信息所进行的交易并未让他们获得更好的收益,甚至反而给他们带来了损失,这与Barberand O’dean等学者所发现的个人投资者行为相类似。     

基于博弈论的我国碳市场监管制度研究

碳市场作为一个具有环境属性的新兴市场,在推进社会生态文明建设上具有重要的地位,但是因为没有辅之完善健全的监督管理措施,碳交易市场的发展速度受到了阻碍。文章运用博弈论的知识构建碳交易市场中交易者与政府监管部门的博弈模型,进行混合策略分析,得出纳什均衡解。结果表明均衡解与违规收益、机会成本、监管成本和政府处罚有关。为了保证碳市场的健康与安全地运转,文章从政府监管成本、交易者机会成本、违规行为、处罚力度4个方面提出建议,规范碳交易市场的监督制度,保证碳市场的良好交易氛围。     

内部交易者的交易行为分析

本文以 Kyle的单期模型为基础 ,通过假设内部交易者无法获得对交易风险资产流动价值的完全信息及市场无法达到标准形式的半强式有效 ,而是一种弱式有效 ,重新分析了内部交易者的交易策略和最终收益 ,从而将 Kyle模型做了推广。本文得出的结论是 ,当内部交易者观测到的信号对交易资产真实流动价值存在扭曲时 ,内部交易者的交易行为变得更为复杂 ;弱式的市场有效性条件和流动价值信号的扭曲可加强内部交易者的信息垄断地位 ,为其相应的策略交易带来更多的收益。     

Fisher’s hypothesis,survey-based expectations and asymmetric adjustments: Empirical evidence from South Africa

Our study re-examines Fisher’s hypothesis for the South African economy in the post-inflation targeting era and presents two empirical novelties over preceding works for the same country. Firstly, we examine Fisher effect by making use of survey-based inflation expectations data for financial analysts, business sector, trade unions and households, hence making our study more disaggregate in nature. Secondly, we examine both short-run and long-run asymmetric cointegration effects in Fisher’s relation using the nonlinear autoregressive distributive lag (NARDL) model as an econometric framework. For the full quarterly sample of 2002:01 – 2019:04, our study finds interest rates respond more aggressively to falling expectations than rising ones, with a full Fisher effect found for financial analysts, partial effects for households and business, and no effect for trade unions. However, when the data is split into two sub-samples corresponding to pre- and post-financial crisis periods, we observe changing dynamics in which interest rates respond more aggressively to rising inflation, with partial effects being also found for trade unions. Policy recommendations based on our study are offered.

     

Indirect exporters and importers

This paper analyses the relation between firms’ productivity and the different modes of participation in international trade. In particular, it accounts for the possibility that firms can not only export their products, but also internationally source their inputs, either directly or indirectly. Using a cross section of firm level data for several advanced and developing economies, the study confirms the productivity-sorting prediction according to which domestic firms are less efficient than those that resort to an export intermediary, while the latter are less productive than producers which export directly. We show that the same sorting exists on the import side. By considering firms involved in both exporting and importing activities, we also find that direct two-way traders are on average more productive than firms trading indirectly on one of the two trade sides. The latter are in turn more efficient than indirect two-way traders. Finally, we investigate the effects of source-country characteristics on the sorting of firms into different modes of international trade.     

噪声交易与股票流动性:兼对“正(负)相关”理论的评析及“流动性黑洞”现象的解释

噪声交易与股票流动性都是行为金融研究的重点，但二者的相关性问题学界一直未能达成一致，"正负之争"不休。文章改进Kyle （1985）的假设，构建符合中国实际的流动性数理模型，模型表明：噪声交易与流动性负相关，且相关关系受信息不对称、风险厌恶度等因素的影响。进一步，文章以中国沪深300指数的成分股数据证实了"噪声交易-流动性"关系，发现其存在显著的月历效应和市场行情效应。文章对"正（负）相关"理论进行了梳理和评析，为争论的清晰化、明朗化做出贡献。     

Voluntary Disclosure and Informed Trading*

This study analyzes the impact of informed trading on voluntary corporate disclosure in the presence of two factors: the cost of disclosure and the value of a manager's informedness. In the absence of both factors, informed trading has no impact on disclosure even when traders are not certain whether the manager has information. When disclosure is costly, informed trading serves as a free substitute for the disclosure of favorable information, and reduces disclosure. Surprisingly, when the manager's informedness is valuable for the firm, informed trading can also increase disclosure. Traders can discover unfavorable information about the firm, so managers with such information have less incentive to pool with uninformed managers and disclose to show that they are informed. The study also demonstrates that informed trading can have either a positive or a negative effect on firm value by crowding in or crowding out information production in the firm. These results hold for general information structures and are robust if traders can choose how much information can be acquired.     

FORMAL–INFORMAL ECONOMY LINKAGES AND UNEMPLOYMENT IN SOUTH AFRICA

South Africa's high unemployment and small informal economy has been attributed to barriers to entry in informal labour markets. We develop a general equilibrium model based on a typology of informal activities that captures formal/informal linkages in product and labour markets. Simulations reveal that trade liberalisation increases formal employment, hurts informal producers, and favours informal traders and may explain the dominance of traders instead of producers. Wage subsidies also raise employment but further heighten competition for informal producers. Cash transfers favour informal employment, albeit with a fiscal burden. Results confirm the role of formal/informal linkages and product markets in explaining policy outcomes.     

Economic and Geographical Distance: Explaining Mercosur Sectoral Exports to the EU

The objective of this paper is to apply a modified gravity model to annual exports disaggregated by sector, from MERCOSUR + Chile to the 15 current members of the EU. In doing so, we aimed to classify sectors according to their sensitivity to geographical and economic distance and to identify which commodities enjoy export strength even without further progress in trade liberalisation with the EU. In the estimation we made use of two additional explanatory variables which are found to be relevant when explaining trade, namely, infrastructure and exchange rates. An exchange rate index is built that takes into account protection. Our results support the view that different sectors have a different sensitivity to distance and highlight the importance of using disaggregated data when analysing international trade flows.     

LIBERALISING TRADE IN SOUTH AFRICA: A SURVEY OF COMPUTABLE GENERAL EQUILIBRIUM STUDIES

This paper reviews applications of computable general equilibrium models to trade liberalisation in South Africa. It focuses on economic structure, data, macroeconomic closure and results of the models. The models project that trade liberalisation has had small positive impacts on growth. Poverty and inequality outcomes are less clear cut and depend on the model used. Models with fully integrated micro data find that poverty has worsened slightly while inequality has risen. Aggregated models predict that poverty has been reduced by small amounts. Dynamic models report rising inequality but falling poverty incidence. The paper identifies areas for future research.     

Trading firms in the services sectors: comparable evidence from four EU countries

We establish a set of stylised facts for trade and trading firms in five market services sectors using comparable firm- and activity-level data from four EU countries. Our analysis shows that exports account for much lower shares of overall sales in the services sectors than in manufacturing. This is because fewer firms are engaged in trade in the services sectors and also because within particular sectors firms trade a lower share of their sales on average. Services producers trade mostly goods, but in terms of value, trade in services is much more important to them than to manufacturers. Larger and more productive firms are more likely to be two-way traders and to engage in both goods and services trade. Trade by services firms is somewhat less dominated by firms that both export and import than trade by manufacturing firms. Few firms export many services or to many countries. The value of services exports is increasing in the number of markets served but not necessarily in the number of services traded.