外贸企业应对网络信息化的思考

一、电子商务对外贸企业的影响 1．网络贸易将会大大降低买卖双方的交易成本。买卖双方通过网络直接接触，无需贸易中介的参与，减少了交易的中间环节；参与交易的各方只需支付较低的网络通信和管理费用就可获得存储、交换和处理信息，节省了资金，降低了成本；由于internet是全球性开放网络，有利于交易双方获得完整信息。降低了市场上的搜寻成本。减少了交易的不确定性；在网上直接传递电子单证，既节约了纸单证的制作费用，又可缩短交单结汇时间。加快资金周转，节省利息开支。     

声誉、搜寻成本与网上交易市场均衡

本文在搜寻理论的框架内分析了在卖家声誉存在差异的情况下,网上拍卖市场搜寻成本对价格水平和价格离差的影响,进而考察了搜寻成本对网上市场声誉机制的影响。本文的结论是:尽管搜索工具提高了网上交易市场的效率,但网上交易市场仍存在不可忽视的搜寻成本;较高的搜寻成本导致不同声誉水平的卖家同时存在于网上交易市场,高声誉卖家制定的价格较高,低声誉卖家制定的价格较低;搜寻效率的提高可以降低均衡价格水平,网站提供的推广服务也可以降低搜寻成本,降低均衡价格水平。模型很好地解释了网上拍卖市场中的一些现象,也与最近文献的经验事实有较好的吻合。     

声誉、搜寻成本与网上交易市场均衡

本文在搜寻理论的框架内分析了在卖家声誉存在差异的情况下,网上拍卖市场搜寻成本对价格水平和价格离差的影响,进而考察了搜寻成本对网上市场声誉机制的影响。本文的结论是：尽管搜索工具提高了网上交易市场的效率,但网上交易市场仍存在不可忽视的搜寻成本;较高的搜寻成本导致不同声誉水平的卖家同时存在于网上交易市场,高声誉卖家制定的价格较高,低声誉卖家制定的价格较低;搜寻效率的提高可以降低均衡价格水平,网站提供的推广服务也可以降低搜寻成本,降低均衡价格水平。模型很好地解释了网上拍卖市场中的一些现象,也与最近文献的经验事实有较好的吻合。     

搜寻理论的经济学社会学实证

搜寻理论是信息经济学的一个重要组成部分。在现实生活中,价格离散,信息不完全以及由此而至的搜寻成本,增加了人们交易的成本。减少搜寻成本,将提高社会的交易水平,促进社会经济的发展。     

浅析网络市场中的"价格离散"现象

“价格离散”指的就是同样的产品具有不同价格。按照传统经济学的观点，既然Internet大大地降低了搜寻成本，消费者就能够获得更多的产品信息，更容易进行价格比较，价格的离散就应该会更低。但已有的许多统计结果表明，价格离散现象在网络市场（在线市场）不仅存在，而且其离散幅度大于实物市场（离线市场）。因此，分析价格离散的原因，探讨减少价格离散的方法一直是经济学家所关注的问题。本文从网络产品质量信息不对称性的角度，对网络市场中价格离散现象产生的原因提出了基于“柠檬市场”理论的解释，并对消除和减少网络市场中价格离散、提高网络市场交易效率进行了分析。     

价格离散、信息搜寻与团购行为

团购行为是当今消费行为学中的一个重要现象,源自市场和产品信息不对称的双重因素是导致消费者行为变化的根本原因。基于产品信息的价格函数模型,分析团购有利于消费者实现信息共享,减少搜寻成本,降低与企业间的信息不对称,减少消费行为的不确定性,从而获得更大的消费效用的结论。     

信息、交易费用与网络供应链

一、信息、网络和交易费用经济活动中的信息,本质上是一种市场参与者的知识与经济环境知识的事件状态(主客观不确定性)之间的概率性建构的知识差。在市场机制中,信息作为经济活动的输入,通过价格信息来协调经济活动;作为经济活动的输出,通过作用于供需决策来协调产品的生产。传统市场由于其分散性、不稳定性等原因,价格离散是不可避免的。这引起了市场参与者的信息不完全性,进而为了降低决策中的不确定性,开始对市场信息进行搜寻。技术进步尤其是网络的广泛应用相当于提供给市场参与者一个有关产品和服务信息的专家系统,从而能够了解比以往…     

信息选择与经验价格

本从信息经济学的角度，分析了食盐市场，高档汽车市场，彩电市场的价格制定与形成，指出价格围绕价值的波动是该市场的主要参与朴素博弈的结果。价格博弈的实质是信息博弈，谁拥有的私人信息多，谁就能在博弈中取得主动，根据上述分析，提出了“经验价格”，“经验成本”的系列新概念，认为市场价格之和或商品价值与买经验价格之关构成的。经验价格源于买或卖的私人信息，是对其为搜寻信息所付出成本的奖励效用。经验成本则是当事人以当时经验认为的付出。     

网络零售市场中价格离散的影响因素

在网络零售市场上面，价格是消费者最敏感的因素，网络零售市场上面普遍存在价格差别和价格离散现象，从网络零售商的角度来看，网上价格离散有各种不同的原因。分析网上价格离散的影响因素，可以帮助网罗零售商制定有效的价格战略和正确的定价方法，对网络零售市场的发展具有重要的意义。     

消费者搜寻、企业竞争与政府规制——文献综述

大量的文献研究表明,消费者在市场交易前搜寻商品信息的经济行为模式和成本深刻影响着产业组织的结构、行为与绩效。通过对文献的进一步考察发现,目前的研究可以从三个方面的进一步深入,一是放松消费者与企业完全知道均衡价格分布的假设;二是放开消费者第一次搜寻无成本的假设;三是将消费者搜寻扩展为价格搜寻与属性搜寻,研究异质商品市场上的消费者搜寻、企业竞争以及社会福利的变化。     

Approximate tâtonnement processes

Summary We introduce a probabilistic model for price adjustment in an exchange economy which approximates the classical Walras tâtonnement process while avoiding many of its unrealistic features. The model is decentralized in that the trades permitted to an agent and the resulting price changes depend only on the commodity vector currently held by that agent, and not on the commodity vectors held by the other agents in the economy. Our results will show that the Walras tâtonnement process can be decentralized without changing its behavior on the macroeconomic scale. Our model has a finite set of commodities, a market maker who adjusts prices, and a large finite set of agents who trade only with the market maker. Each agent has a demand function depending on his commodity vector and the price vector. At each discrete time, one agent is chosen at random and exchanges his current commodity vector for his demand vector. Then the market maker adjusts the price vector by an amount which depends on the selected agent's commodity vector and the current price. Prices are adjusted rapidly enough to avoid prolonged trading at the wrong price, but slowly enough so that a substantial price change will depend on a significant simple of agents. The main result shows that with probability arbitrarily close to one the price will rapidly approach and then remain close to an equilibrium value, following a path which is close to the price path of the corresponding tâtonnement process.     

异质信念、投机均衡与农产品期货定价*

农产品期货市场套利并不充分,交易者也不是完全理性的。本文假设农产品期货市场有限套利、交易者异质信念并遵循“经验法则”预期,构建了农产品期货投机均衡定价模型,并认为集中竞价规则下产生的农产品期货价格是由交易者的预期决定的;前期期货价格水平、现货价格和前期期货价格的变动趋势、不同类型交易者的比例结构及其预期模式共同影响农产品期货价格的形成与波动;基本分析法交易者占主导地位的农产品期货市场具有更高的套期保值与价格发现效率。针对中国七种主要农产品期货的实证结果显示,农产品期货投机均衡定价模型对解释中国农产品期货价格的形成与波动是有效的。这意味着在期货行情系统中实时披露现货价格信息,培育和引导交易者运用基本分析法预测期货价格走势,有助于提升农产品期货市场的效率。     

Commodity prices and related equity prices

This paper shows that commodity‐sensitive stock price indices have strong power in predicting nominal and real commodity prices at short horizons (one‐month‐ahead predictions) using both in‐ and out‐of‐sample tests. The forecasts based on commodity‐sensitive stock price indices are able to significantly outperform naïve no‐change forecasts. For example, the one‐month‐ahead forecasts for nominal commodity prices reduce the mean squared prediction error by between 1.5% (for natural gas prices) and 20% (for copper prices). Moreover, the one‐month‐ahead directional forecast is found to perform significantly better than a 50:50 coin toss. As stock prices are not subject to revision, the proposed variable, which reflects timely and readily available market information, can potentially be a valuable predictor and thereby help to improve the accuracy of commodity price forecasts.     

(Monopolistic) resource extraction and limit pricing: The market penetration of competitively produced synfuels

This paper analyzes the market penetration of a competitively produced synfuel, e.g., solar energy, in a market that is initially dominated by a resource extracting monopoly. The availability of the renewable substitute depends not only on the price/cost ratio but also on the installed capacities, which reflect historical investments. As a consequence, the resource monopoly faces a discontinuous residual demand schedule. The dynamic interactions between the resource cartel and the synfuel industry are modelled as a differential game; the (open loop) Nash equilibrium is applied to this game. It will be shown that the commodity price will exceed the production costs of the backstop and that the transition from the periods of resource dependence to the backstop technology will be gradual.     

A behavioral cobweb-like commodity market model with heterogeneous speculators

According to empirical studies, speculators place significant orders in commodity markets and may cause bubbles and crashes. This paper develops a cobweb-like commodity market model that takes into account the behavior of technical and fundamental speculators. We show that interactions between consumers, producers and heterogeneous speculators may produce price dynamics which mimics the cyclical price motion of actual commodity markets, i.e., irregular switches between bullish and bearish price developments. Moreover, we find that the impact of speculators on price dynamics is non-trivial: depending on the market structure, speculative transactions may either be beneficial or harmful for market stability.     

Impacts of Institutional Intervention on Price Transmissions: The Case of the Ethiopian Commodity Exchange

In the aftermath of the market liberalization reforms, interventions in developing countries shifted toward building institutions. One of such interventions is the introduction of commodity exchanges. The theoretical justification is that commoditization reduces the high transaction costs associated with the information and enforcement problems characterizing agricultural markets of these countries. However it is not known whether these potential gains are transmitted to the various markets along a value chain. By taking the Ethiopian Commodity Exchange (ECX) as a case, this paper examines the impacts of the introduction of the commodity exchange in transmitting price signals along the coffee value chain (world‐export‐auction‐producer prices). We found that both the speed and symmetry of transmission remains weak even after the launch of ECX. At each level, the market chain was found to favor buyers. This implies that not only the country's gains from export are sub‐optimal, the cumulative burden is on the millions of smallholder farmers who are located at the bottom of the chain. In a context where local agricultural markets remain traditional and export markets barely competitive, the introduction of the commodity exchange will have limited impacts in improving the performance of markets in transmitting price signals. Other policy measures to further liberalize both local and export markets are required.     

Cross market predictions for commodity prices

This paper shows that commodity prices can be predicted from cross-market information by establishing long-run cross-market commodity price equilibrium models, which are characterized by a linear relation between prices across different markets. Using data from five representative commodity markets (oil, copper, gold, corn, and cattle) during the period 2005–2018, we demonstrate that oil and industrial metal markets have formed a long-run price equilibrium with other markets across different commodity families. However, agriculture and gold markets do not tend to have long-run price equilibrium relations with other commodity markets. Furthermore, we show that the absence of a price equilibrium is due to the cross-market liquidity interference effect. After we control for the liquidity effect, long-run cross-market commodity price equilibrium relations are reestablished for agriculture and gold markets. These results can aid in demonstrating that liquidity can capture most of the missing information that is not reflected in price dynamics in less liquid markets, such as agriculture and gold markets. Therefore, less liquid commodity price predictions require both prices and liquidity levels from cross-markets, while liquid commodity prices (oil and metal) can be predicted based solely on cross-market prices.     

Conservative traders,natural selection and market efficiency

This paper examines the impact of conservative traders on market efficiency in an evolutionary model of a commodity futures market. This paper shows that the long-run market outcome is informationally efficient, as long as in every period there is a positive probability that entering traders are more conservative than their predecessors. Conservative traders are those who correctly predict the spot price with a positive probability, and more importantly, who in their mistakes err on the side of caution, and rarely overpredict the spot price as buyers, and underpredict the spot price as sellers. This result does not require entry of traders with better information than their predecessors.     

COMMODITY BALANCES AND NATIONAL ACCOUNTS: A SAM PERSPECTIVE

This paper is concerned with the treatment of commodity and activity balances in a national accounts context. It makes use of a general method for reducing the size of a social accounting matrix (SAM) by apportioning the elements of one or more accounts to the rest. The national accounts are looked at in terms of their usefulness for policy analysis, not least analysis of the impact of price changes. The SNA convention of separately distinguishing activities and commodities is endorsed. However, in contrast to the SNA, it is argued that for analytic purposes commodity transactions should be recorded at market prices, with a separate account for each of the markets for a given commodity in which a distinct price prevails. The SNA SAM is shown to be a reduced form of the SAM resulting from this recommended treatment of commodity transactions, while a further round of reductions (apportionments) yields SAMs which are familiar from input-output analysis, in which activities and commodities are not separately distinguished. It is argued that no special effort would be required to produce SAMs in which commodity balances are recorded at market prices as recommended here (the necessary data are also required to produce the conventional SNA tableaux), and that all reduced form versions of such SAMs, including the SNA, are inferior as a basis for the analysis of price effects on the structure of production.     

Commodity price cycles and heterogeneous speculators: a STAR–GARCH model

We propose an empirical commodity market model with heterogeneous speculators. While the power of trend-extrapolating chartists is constant over time, the symmetric impact of stabilizing fundamentalists adjusts endogenously according to market circumstances: Using monthly data for various commodities such as cotton, sugar or zinc, our STAR–GARCH model indicates that their influence positively depends on the distance between the commodity price and its long-run equilibrium value. Fundamentalists seem to become more and more convinced that mean reversion will set in as the mispricing enlarges. Commodity price cycles may thus emerge due to the nonlinear interplay between different trader types. The paper represents the authors’ personal opinion and does not necessarily reflect the views of the Deutsche Bundesbank.