Equilibrium price and advertisement distributions

We consider an economy where many sellers sell identical goods to many buyers. Each seller has a unit supply and each buyer has a unit demand. The only possible information flow about prices is through costly advertising. We show that in equilibrium the sellers use mixed strategies in pricing which leads to price and advertisement distributions. With convex advertising costs each seller sends only one advertisement in the market. We also delineate a class of advertising costs which ensures that sellers may send multiple advertisements in equilibrium. Higher prices are advertised more than lower prices.     

Buyer–seller networks with demand shocks and intermediation

We present a model in which buyers and sellers use links to trade with each other. Each seller produces a good which can be one of two types. Buyers are ex ante identical but receive specification or valuation shocks after the links are formed. We show that efficient networks are stable and that severing a link in an efficient network results in a higher price for the buyer but a lower price for the seller. We also examine network intermediation when sellers (buyers) form links sequentially. When sellers form links sequentially, the first seller becomes an intermediary and shares links with other sellers; this makes all sellers better off. However, when buyers form links sequentially, buyers may or may not share links. If links are shared multiple intermediaries result.     

Descending price multi-item auctions

We propose a simultaneous descending price auction mechanism to sell multiple heterogeneous items, each owned by a distinct seller, to a number of buyers. Each buyer has known private valuations on items, and wants at most one item. We show that if the sellers follow a descending price offer procedure and the buyers follow a greedy strategy for accepting the offers, the auction results in a nearly efficient allocation, and terminates close to a competitive equilibrium price vector. The descending price offer strategy of the sellers is close to a Nash equilibrium. However, we show that the buyers are better off waiting in our auction. There is a maximum limit (corresponding to the minimum competitive equilibrium price vector) till which they can wait without running into the risk of not winning any item. If the buyers wait within this limit, the prices can be brought arbitrarily close to a uniquely defined competitive equilibrium price vector.     

Common-value auction versus posted-price selling: an agent-based model approach

Previous theoretical work has compared a private-value auction and posted-price market, and an affiliated-value auction and a posted-price market to determine the selling method preferred by sellers. Much less, however, is known about the seller’s preferred selling method when the buyers have a common value of the item. Our objective is to determine if a first-price auction or a posted-price market provides a seller with the larger expected revenue when buyers have a common value of the item being sold. An agent-based posted-price market and an agent-based first-price common-value auction with a reserve price are developed to compare these selling methods. Holding the buyers’ uncertainty about the value of the item constant, the seller prefers the posted-price market when the seller has no uncertainty about the item’s value. When the seller has an equal level of uncertainty as the buyers, the seller’s expected revenue for each market is similar. As the seller’s uncertainty increases beyond the level of the buyers’ uncertainty, the auction with a reserve price eventually becomes the preferred choice.     

Intermediaries,Credibility and Incentives to Collude

A seller contracts and potentially colludes with a certification intermediary. We investigate the intermediary’s incentives to collude, her pricing strategy, and the extent to which buyers rely on the intermediary’s announcements. The probability of collusion is an endogenous variable, determined by the intermediary’s pricing strategy. The extent to which the market relies on the intermediary’s reports, the certification price and the intermediary’s profit decrease as the intermediary becomes less patient. By making certification mandatory, the intermediary loses her ability to screen out low‐quality sellers, which increases the probability of collusion.     

The Role of Coordination Bias in Platform Competition

This paper considers platform competition in a two‐sided market that includes buyers and sellers. One of the platforms benefits from a favorable coordination bias in the market, in that for this platform it is less costly than for the other platform to convince customers that the two sides will coordinate on joining it. We find that the degree of the coordination bias affects the platform's decision regarding the business model (i.e., whether to subsidize buyers or sellers), the access fees, and the size of the platform. A slight increase in the coordination bias may induce the advantaged platform to switch from subsidizing sellers to subsidizing buyers, or induce the disadvantaged platform to switch from subsidizing buyers to subsidizing sellers. Moreover, in such a case the advantaged platform switches from oversupplying to undersupplying sellers, and the disadvantaged platform switches from undersupplying to oversupplying sellers.     

On axiomatizations of the Shapley value for assignment games

We consider the problem of axiomatizing the Shapley value on the class of assignment games. It turns out that several axiomatizations of the Shapley value on the class of all TU-games do not characterize this solution on the class of assignment games. However, when considering an assignment game as a (communication) graph game where the game is simply the assignment game and the graph is a corresponding bipartite graph where buyers (sellers) are connected with sellers (buyers) only, we show that Myerson’s component efficiency and fairness axioms do characterize the Shapley value on the class of assignment games. Moreover, these two axioms have a natural interpretation for assignment games. Component efficiency yields submarket efficiency stating that the sum of the payoffs of all players in a submarket equals the worth of that submarket, where a submarket is a set of buyers and sellers such that all buyers in this set have zero valuation for the goods offered by the sellers outside the set, and all buyers outside the set have zero valuations for the goods offered by sellers inside the set. Fairness of the graph game solution boils down to valuation fairness stating that only changing the valuation of one particular buyer for the good offered by a particular seller changes the payoffs of this buyer and seller by the same amount.     

On second-price auctions and imperfect competition

Consider two sellers each of whom has one unit of an indivisible good and two buyers each of whom is interested in buying one unit. The sellers simultaneously set reserve prices and use second-price auctions as rationing device. An equilibrium in pure strategies where each seller has a regular customer is characterized. The result is applied in order to demonstrate that not allowing sellers to use second-price auctions may enhance total surplus.     

中国房地产交易真的是卖方市场吗？——基于双边随机边界模型的实证研究

科学测算房地产交易市场买卖双方议价能力对市场价格形成的影响作用，是当前政府制定“因地施策”宏观调控机制的重要前提。采用双边随机边界模型，考察房地产交易环节中买卖双方议价能力的差异,结果表明：（1）买卖双方讨价还价因素对商品房销售价格的最终形成存在显著影响；（2）从全国平均水平看，对于整体市场以及住宅、写字楼和商铺等细分市场，卖房者议价能力在双方讨价还价过程中占主导地位，但买方议价能力的影响作用也不容忽视；（3）从一线、新一线、二线和三线城市角度看，除了一线城市商铺市场以及三线城市总体城市、住宅市场和写字楼市场外，其他均处于卖方市场阶段。     

Buyer information and the hedonic: The impact of a seller disclosure on the implicit price for airport noise

Revealed preference methods like the hedonic model generally assume economic agents have access to publicly available information and use it effectively. In the housing market, the recent proliferation of seller disclosure laws suggests that policymakers perceive buyers to be less than “fully informed,” presumably since they face higher information acquisition costs than sellers. The introduction of an airport noise disclosure in the residential housing market surrounding the Raleigh–Durham International Airport is used as a quasi-random experiment to analyze the impact of this type of information asymmetry between buyers and sellers on housing prices. The results from a regression analysis that controls for potential spatial and temporal confounders, suggest that the airport noise disclosure reduced the value of houses most heavily impacted by airport noise by 2.9 percent. This represents approximately a 37 percentage point increase in the implicit price of airport noise. The results provide evidence that publicly available information, such as that available for airport noise, may not be adequately considered by all buyers. They also suggest that the information environment should be carefully considered when using housing data and the hedonic model to value urban amenities and disamenities.     

The influence of seller learning and time constraints on sequential bargaining in an artificial perishable goods market

This paper investigates the formation of prices in a perishable goods market where agents bargain repeatedly through pair-wise interactions. After extensive field observations, we chose to focus on two aspects that seem important to actors of this market: the passage of time and update in judgement when gathering information. The main feature of the market is that a seller bargaining with a buyer has incomplete information about buyer's willingness to pay and is not sure how her trading partner will evaluate an offer or compare it with other options. On the other hand, buyers have limited time to look for goods and cannot meet all possible sellers before making a decision. Hence agents cannot calculate the best price to offer but receive information through limited interactions, and use this information to choose their actions.An agent-based model was built to represent a framework that mimics the observed market institution and where agent's possible behaviors and learning was made as consistent as possible with gathered data. Simulations were run, first for sensitivity analysis concerning main parameters, then to test the dependance of agents’ learning to (a) the time buyers can spend on the market and (b) the frequency of update in learning by sellers. To validate the model, features produced by the simulated market are compared to the stylized facts gathered for negotiation about four goods. We reproduce the main features of the data on the dynamics of offers, transaction prices and agents’ behavior during the bargaining phases.     

Strategic Buying to Prevent Seller Exit

We consider a dynamic oligopoly model in which a seller may drop out of the market when demand for its product is insufficient in the first period. Buyers suffer some disutility if a seller exits the market and so their first‐period purchase decision not only depends on current period preferences and prices, but also on the potential effect that their behavior has on the probability of seller survival. Specifically, some buyers may choose to purchase from the seller with the lower survival probability even though they like the other seller's product better, a behavior that we call “strategic buying.” We analyze how the incidence of strategic buying depends on parameters and also the implications of the strategic buying motive for sellers' first‐period pricing decisions.     

Non‐Neutral and Asymmetric Effects of Neutral Ratings: Evidence From eBay

Seller ratings help overcome adverse selection problems in online transactions between strangers. Using eBay data, we find that auction outcomes are sensitive toward not only positive and negative seller ratings but also neutral ratings. We find that (1) buyers utilize neutral ratings to sort among otherwise identical sellers and value their products and (2) contrary to eBay's opinion, depending on whether a seller is top‐notch or not, neutral ratings can be detrimental or beneficial; for sellers with higher proportions of positive ratings, an increase in neutral ratings decreases sales. For sellers with higher proportion of negative ratings, an increase in neutral ratings increases both sales and revenue. Copyright © 2014 John Wiley & Sons, Ltd.     

The holdout problem and urban sprawl: Experimental evidence

Conventional wisdom as well as economic theory suggests it is more costly to reassemble fragmented land due to transactions costs and strategic bargaining costs. Both costs are expected to increase with the number of sellers. Inefficient allocation of land resources may result including property entropy (Parisi, 2002), urban sprawl (Miceli and Sirmans, 2007) and deteriorating inner cities. Given the difficulty of observing actual values attached by buyers and sellers to land, little empirical evidence exists to support the conventional wisdom and theoretical work. We use experimental methods to examine transactions costs and strategic bargaining costs in a land-assembly market game with one buyer, 1-4 sellers, and complementary exchanges. The buyer’s final earnings vary inversely with the number of sellers, ceteris paribus, indicating an incentive to purchase consolidated land. Delay costs reduce holdout, but result in lower payoffs for both buyers and sellers. Competition between sellers reduces holdout and the buyer’s total purchase price.     

The effects of barriers to entry on monopolistic intermediary online services: The case of a digital library

Online intermediaries (OIs) are becoming increasingly important market institutions. They have low marginal costs and display the indirect network effect, which suggests that the benefit of an intermediary to sellers (buyers) increases with the number of buyers (sellers) connected to that intermediary. OIs may be further characterized by the levels of barriers to entry they face and the direct network effect, i.e., the benefit to a seller decreases with the number of sellers connected to the intermediary. This paper models a digital library where creators sell their works to information users. It is found that a monopolistic digital library with the above characteristics over-serves its creators, which leads them to over-invest in creation, and over-supply information products to consumers. Furthermore, the over-investment is more severe when the barriers to entry in the digital library sector are lower. A counter-intuitive policy implication is that removing barriers to entry in monopolistic markets with the above characteristics does not improve, but rather worsens, social welfare.     

Divergence in Reservation Prices and Its Impact on Housing Market Liquidity: A Theoretical Analysis

In this paper, we build a two-period English auction model to study the relative movements between buyers’ and sellers’ reservation prices in the housing market. We show that changes in sellers’ reservation prices are jointly determined by changes in buyers’ reservation prices, probability of buyers offering a high or low price, and the arrival rate of buyers. When the divergence between the buyers’ and sellers’ reservation prices widens, the probability of sale increases in the upward market and decreases in the downward market, contributing to the increases or decreases in market liquidity.     

First price package auction with many traders

This paper studies a first price package auction in which multiple sellers participate in addition to multiple buyers. We generalize the notion of the profit-target strategy which is first introduced as a truthful strategy in a first price package auction with a single seller by Bernheim and Whinston (1986b). We then show that the set of equilibrium payoffs in profit-target strategies is equal to the bidder-optimal core, and is also equal to the set of coalition-proof Nash equilibria. Using this result, we find that any equilibrium payoff vector is weakly Pareto-dominated by the VCG payoff vector for buyers, and that the Walrasian competitive equilibrium payoff vector is weakly Pareto-dominated by some equilibrium payoff vector for buyers, even if goods are substitutes. This contrasts with the first price package auction with a single seller, in which it is shown that if goods are substitutes, then those three outcomes are payoff-equivalent.     

Optimality and consistency in a differential game with non-renewable resources

Imperfect competition amongst buyers for a non-renewable resource is modeled as a Stackelberg differential game. The buyers may act as a cartel or behave non-cooperatively in setting tariffs, which the sellers take as given. The buyer's optimal policy is not consistent when extraction costs depend on the stock level. Both optimal and consistent, unit and ad valorem tariff's are analyzed. When a buyers' cartel uses a consistent tariff, the sellers may prefer to behave as perfect competitors or a monopolist, depending on the functional form of demand and cost. Non-cooperative buyers who are constrained to act consistently are unable to extract any rent from competitive sellers.     

Can boundedly rational sellers learn to play Nash?

How does Nash pricing compare to pricing with adaptive sellers using reinforcement learning (RL)? We consider a market game similar to Varian’s model (Am Econ Rev 70:651–659, 1980) with two types of consumers differing by the size of their fixed sample search rule and derive the Nash search equilibrium (NSE) strategy (the density, the mean and the variance of the posted price distribution). Our findings are twofold. First, we find that the RL price distribution does not converge in a statistical sense to the NSE one except when competition is à la Bertrand. Second, we show that the qualitative properties of the NSE with respect to a change in buyers‘ search behavior are still valid for the RL distribution. The average price and the variance of both price distributions exhibit similar variations to a change in buyers’ search.     

Group Buying Commitment and Sellers’ Competitive Advantages

This paper examines a model of duopoly firms selling to an exogenously formed buyer group consisting of members with heterogeneous preferences. Two research questions are addressed: (1) when is it optimal for a buyer group to commit to exclusive purchase from a single seller, and (2) how does the presence of group buying and the exclusive purchase commitment associated with it affect firms’ incentives to invest in quality improvement? We find that, even though exclusive purchase commitment benefits buyers when the competing products provide similar quality, it may lower buyer surplus if one product is significantly advantaged and/or the competing products are not highly differentiated horizontally. This result is robust even if the buyer group is formed endogenously. In addition, contingent on the similarity between the competing sellers’ investment costs, the sellers’ incentives to improve quality may be positively or negatively affected by the presence of group buying.