Formation of buyer-seller trade networks in a quality-differentiated product market

Abstract .  We examine the formation of buyer-seller links when exchange can take place only if such a link exists. Sellers produce products of different qualities, and multiple sellers can form a sellers' association to pool their customers setting uniform prices. Buyers form trade links with individual sellers or sellers' associations. We show which buyer-seller links will form and find the set of links that are stable and show how these links influence prices. We also show that a trade network mismatch may occur where a high-quality good remains unsold even without an economy-wide excess supply of goods.     

Convergence to perfect competition of a dynamic matching and bargaining market with two-sided incomplete information and exogenous exit rate

Consider a decentralized, dynamic market with an infinite horizon and incomplete information in which buyers and sellers' values for the traded good are private and independently drawn. Time is discrete, each period has length δ, and each unit of time a large number of new buyers and sellers enter the market. Within a period each buyer is matched with a seller and each seller is matched with zero, one, or more buyers. Every seller runs a first price auction with a reservation price and, if trade occurs, the seller and winning buyer exit with their realized utility. Traders who fail to trade either continue in the market to be rematched or exit at an exogenous rate. We show that in all steady state, perfect Bayesian equilibria, as δ approaches zero, equilibrium prices converge to the Walrasian price and realized allocations converge to the competitive allocation.     

消费者谈判能力与厂商标价策略-模型及基于实验经济学的检验

本文建立的理论模型研究了消费者谈判能力、谈判成本和对商品的偏好程度等几方面对厂商最优标价决策的影响。当消费者谈判能力较弱时,厂商可能策略性地不对商品标价,以获取更大利润,利润大小与消费者的谈判能力呈倒U形关系;而当消费者谈判能力较强时,厂商会选择对商品进行标价以最大化利润;但若消费者谈判能力很弱,消费者很可能因无利可图而放弃购买,这时厂商就会选择标价销售。通过对模型进行模拟实验,模型的结果得到了进一步验证。本文同时证明,在一定条件下,厂商选择策略性不标价可能不是社会最优的,因此需要通过政府强制标价来实现市场有效性。     

Trading networks with price-setting agents

In a wide range of markets, individual buyers and sellers trade through intermediaries, who determine prices via strategic considerations. Typically, not all buyers and sellers have access to the same intermediaries, and they trade at correspondingly different prices that reflect their relative amounts of power in the market. We model this phenomenon using a game in which buyers, sellers, and traders engage in trade on a graph that represents the access each buyer and seller has to the traders. We show that the resulting game always has a subgame perfect Nash equilibrium, and that all equilibria lead to an efficient allocation of goods. Finally, we analyze trader profits in terms of the graph structure — roughly, a trader can command a positive profit if and only if it has an “essential” connection in the network, thus providing a graph-theoretic basis for quantifying the amount of competition among traders.     

Cheating in markets: A laboratory experiment

We develop a two-market model under three conditions: autarky, frictionless free trade, and free trade with cheating. With cheating, buyers can underpay by π% in cross-market trades and sellers can deliver π% of full value. We solve for competitive equilibrium with cheating and obtain novel testable predictions on price, volume and surplus. We test these in a laboratory experiment using parameters intended to challenge the theory. The results are generally consistent with competitive equilibrium. We find evidence of price unification, market segmentation, a cross-market volume of trade lower under cheating than in frictionless free trade, but a higher overall volume.     

Expectations Heterogeneity and Excessive Price Sensitivity in the Land Market

This paper analyses price behaviour in the land market in which the Walrasian auctioneer is absent. Sellers are informed about the land value and post their asking prices; buyers are uninformed, have different opinions, and decide whether or not to accept the sellers' offers. In this market, sellers are "price-makers" with probabilisitic market power : they can influence the sale probability through their asking price. Price may be excessively sensitive to unexpected changes in market conditions. Moreover, buyer heterogeneity may accentuate the excessive price sensitivity. It has been shown that, the more heterogeneous their opinions, the more sensitive are prices.
JEL Classification Numbers: D40, D43, D82, D84, E44, G12.     

Revisiting the Lemons Market

This article extends the standard competitive adverse selection model by allowing for qualitatively different information structures of agents on the informed side of the market. Using the stylized framework of the market for used cars, we examine the welfare properties of equilibria under the assumption that a fraction of the sellers remains uninformed about a parameter that is relevant for their own transaction. Whether market performance increases or decreases in the number of uninformed sellers is shown to depend on (1) the potential gains from trade in the market and (2) the average quality of the sellers' information structure.     

Some factors affecting demand withholding in posted-offer markets

Summary. Both oligopoly theory and experiments are concerned almost uniquely with sellers' behavior. Buyers' ability to exhibit non-trivial behavior in different market institutions remains unaddressed. This paper investigates the impact of three variables (number of buyers, surplus division at the market-clearing price and information revelation) on strategic and fairness-motivated demand withholding. Demand withholding and its ability to force lower prices increase as the number of buyers or the share of surplus earned by the buyers decreases. However, increasing the information revealed to subjects about the surplus inequality favoring sellers mildly facilitates collusion among sellers rather than provoking demand withholding as conjectured.     

Trade prices and supply in the UK economy

Current account imbalances are a major source of instability in the world monetary and trading system. Measures to correct these imbalances have largely involved adjustments to exchange rates. In the international trade literature, when the current account is in deficit, the Marshall-Lerner condition is sufficient for a successful devaluation. However, this partial equilibrium condition — apart from being based on the assumption that supply elasticities are infinite — abstracts from how the domestic economy responds to the change in relative prices. In this paper we develop a model of price and output determination in an open economy with imperpectly competitive markets, and draw a distinction between goods which are exported and those which are supplied to the domestic market. This means that we have to determine jointly both export prices and the domestic price of house sales. We show that as long as there is no money illusion in the labour market a fall in the nominal exchange rate raises domestic and export prices proportionally and leaves trade volumes unaffected. However, shifts in domestic absorption relative to overseas demand — by changing relative prices — cause shifts in the relative supply of exports and domestically sold goods and affect the trade balance. Thus fiscal and monetary measures directed towards reducing domestic absorption are more likely to be successful in correcting current account imbalances than exchange rate depreciation.     

Income distribution and exchange in a dynamic search model

This paper studies the link between income distribution and trade mechanisms in a dynamic search model with two-sided asymmetric information. Buyers and sellers have imperfect information about the income levels of the other group. Furthermore, asymmetry of information about incomes is the source of price dispersion. In such a frictional environment, we capture the effects of a change in inter- and intra-class income distribution on the trade mechanism, which is represented by the expected trade volume and the flux of buyers and sellers in the market.     

The Role of Chonsei as a Price Protector in the Korean Housing Market

In this study, we investigate whether ‘Chonsei,’ the distinctive type of housing contract system in Korea, has a favorable impact on house prices during a market downturn. We show the mechanism in which Chonsei prevents a sharp drop in house prices based on sellers’ loss aversion behavior. Moreover, using data on the Seoul condominium (i.e. apartment) market during the 2006–2017 period, we find that Chonsei prices have a negative impact on the housing trade volume in a market recession. This finding is consistent with our argument that loss aversion behavior appears with regard to the rise in Chonsei prices and thereby Chonsei functions as a price protector in the Korean housing market.     

Sunk costs and fairness in incomplete information bargaining

We study a bilateral trading relationship in which one agent, the seller, can make a nonrecoverable investment in order to generate potential gains from trade. Afterwards, the seller makes a price offer that the buyer can either accept or reject. If agents are fairminded, sellers who are known by the buyer to have high investment costs are predicted to charge higher prices. If the investment cost is private information, low-cost sellers should price more aggressively and high-cost sellers less aggressively than under complete information, giving rise to disagreement and/or underinvestment. Our experiment support these predictions.     

Dynamic price competition

We consider the model of price competition for a single buyer among many sellers in a dynamic environment. The surplus from each trade is allowed to depend on the path of previous purchases, and as a result, the model captures phenomena such as learning by doing and habit formation in consumption.We characterize Markovian equilibria for finite and infinite horizon versions of the model and show that the stationary infinite horizon version of the model possesses an efficient equilibrium where all the sellers receive an equilibrium payoff equal to their marginal contribution to the social welfare.     

Option to wait in a search model

We consider a standard search model with buyers and sellers. Upon meeting the buyers make a take-it-or-leave-it offer, but the sellers have an option not to trade immediately but wait for more agents to appear. If more buyers come, there is excess demand, and the buyers engage in auction to get the good. Analogously, if more sellers come, the sellers engage in a Bertrand-type pricing game to sell the object. The option to wait restricts the price offer of the buyer; in an equilibrium in which trades are consummated without delay there is a unique price offer for the buyer.JEL Classification: C78, D44, D831     

Trading mechanism selection with directed search when buyers are risk averse

We endogenize the trading mechanism selection in a model of directed search with risk averse buyers and show that the unique symmetric equilibrium entails all sellers using fixed price trading. Mechanisms that prescribe the sale price as a function of the realized demand (auctions, bargaining, discount pricing, etc.) expose buyers to the “price risk”, the uncertainty of not knowing how much to pay in advance. Fixed price trading eliminates the price risk, which is why risk averse customers accept paying more to shop at such stores.     

Optimality versus practicality in market design: A comparison of two double auctions

We consider a market for indivisible items with m buyers and m sellers. Traders privately know their values/costs, which are statistically dependent. Two mechanisms are considered. The buyer's bid double auction collects bids and asks from traders and determines the allocation by selecting a market-clearing price. It fails to achieve all possible gains from trade because of strategic bidding. The designed mechanism is a revelation mechanism in which honest reporting of values/costs is incentive compatible and all gains from trade are achieved. This optimality, however, comes at the expense of plausibility: (i) the monetary transfers among the traders are defined in terms of the traders' beliefs about each other's value/cost; (ii) a trader may suffer a loss ex post; (iii) the mechanism may run a surplus/deficit ex post. We compare the virtues of the simple yet mildly inefficient buyer's bid double auction to the flawed yet perfectly efficient designed mechanism.     

Market collusion and the politics of protection

This paper investigates the relationship between trade and competition policy within a model where market collusion and protectionist lobbying are themselves related. Collusion and lobbying are modeled as joint products of the same collective effort of firms. In equilibrium, firms cannot achieve greater cooperation in one dimension without reducing it in the other. A trade agreement that limits the effectiveness of lobbying may cause firms to increase market collusion, thereby increasing the domestic price. Thus, international trade agreements may run counter to the goals of competition policy. On the other side, a more restrictive competition policy is shown to either reduce the domestic price or reduce import protection. Thus, competition policy tends to promote trade policy goals. The reason is that restrictive competition policy undermines collusion at the source—it decreases the per-firm benefit to collusion relative to the gains from deviating—reducing firm cooperation in both dimensions.     

Internet auctions with many traders

We study a multi-unit auction environment similar to eBay. Sellers, each with a single unit of a homogeneous good, set reserve prices at their own second-price auctions. Each buyer has private value for the good and wishes to acquire a single unit. Buyers can bid as often as they like and move between auctions. We characterize a perfect Bayesian equilibrium for this decentralized dynamic mechanism in which, conditional on reserve prices, an efficient set of trades occurs at a uniform price. In a large but finite market, the sellers set reserve prices equal to their true costs under a very mild distributional assumption, so ex post efficiency is achieved. Buyers’ strategies in this equilibrium are simple and do not depend on their beliefs about other buyers’ valuations, or the number of buyers and sellers.     

WHO SEARCHES?*

We consider a directed search model with buyers and sellers and determine whether buyers look for sellers or vice versa. The buyers and sellers can choose to search or wait; what they do in equilibrium depends on the relative size of the two populations and the price formation mechanism. We study bargaining and auctions and find that when one population is much larger than the other the former searches and the latter waits. Under auction with roughly equal populations some buyers and sellers search and some wait. Our results challenge the practice of postulating who searches and who waits.     

Middle Men: The Visible Market‐Makers

This paper presents a framework in which middlemen emerge to intermediate between ex‐ante homogeneous buyers and sellers in the presence of search frictions. Middlemen announce prices, and hold an inventory to provide more sure services. Middlemen can mitigate trade imbalances with price competition. Using this framework I illustrate how the frictionless limit can emerge and how middlemen can implement the short‐side principle for the market price to be Walrasian. The recent progress in the literature on intermediation will also be discussed.