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.     

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.     

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.     

List price and sales prices of residential properties during booms and busts

This paper investigates the relationship between the list and sale price of residential properties over the housing cycle. In down or normal markets the list price generally exceeds the sales price; however, when the housing market is strong, homes sell for more than their list price. This observation is not consistent with the assumptions made in the standard model of home sellers’ search behavior. We consider alternative models. In one, sellers set list prices based on their expectations of future changes in sales prices and the arrival rate of buyers; however, demand shocks occur. This model partially explains our data from the Belfast, U.K. housing market, but it fails to predict the list to sales price ratio during a sustained housing boom. We next describe a model where sellers’ endogenously select their search mechanism depending on the strength of the housing market. We find support for the conjecture that sellers switch to an auction-like model during housing booms. There also is evidence that during a downturn in the market, sellers’ list prices are sticky.     

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 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.     

Natural oligopolies with exogenous sunk costs: A non-Suttonian result

In a spatial competition model with exogenous fixed costs and divisible goods, we obtain non-Suttonian results. When the economy is infinitely replicated, the number of firms does go to infinity but, as consumers’ income goes to infinity, the equilibrium number of firms tends toward a finite value. This occurs because the global demand to each firm becomes in the limit infinitely sensitive to price differentials since they give then rise to infinitely large differences in purchase expenditure.     

Reputation,Trust, and Rebates: How Online Auction Markets Can Improve Their Feedback Mechanisms

Reputation systems constitute an important institution, helping sustain trust in online auction markets. However, only half of buyers leave feedback after transactions, and nearly all feedback is positive. In this paper, I propose a mechanism whereby sellers can provide rebates (not necessarily in monetary form) to buyers contingent upon buyers' provision of reports. Using a game theoretical model, I show how the mechanism can increase unbiased reporting. There exists a pooling equilibrium where both good and bad sellers choose the rebate option, even though their true types are revealed through feedback. The mechanism also induces bad sellers to improve the quality of the contract.     

Wealth creation from high-tech divestitures

We measure the change in value to sellers and buyers of divested high-tech assets. Sellers and buyers experience favorable announcement effects in response to high-tech divestitures. However, buyers of divested high-tech assets experience more favorable announcement effects than sellers, which is opposite of the related research findings on other types of divestitures. Based on a cross-sectional analysis, the announcement effects for sellers of high-tech assets are more favorable when there is an investment bank advisor, the transaction price is disclosed, and the size of the divestiture is large. The announcement effects for buyers of high-tech assets were also more favorable when there was an investment bank advisor during the tech-bubble period. Overall, the results suggest that the stock price behavior in response to divestitures of high-tech assets is distinctly different from that of other types of divestitures.     

On the convergence of genetic learning in a double auction market

We study the learning behavior of a population of buyers and a population of sellers whose members are repeatedly randomly matched to engage in a sealed bid double auction. The agents are assumed to be boundedly rational and choose their strategies by imitating successful behavior and adding innovations triggered by random errors or communication with other agents. This process is modelled by a two-population genetic algorithm. A general characterization of the equilibria in mixed population distributions is given and it is shown analytically that only one price equilibria are attractive for the GA dynamics. Simulation results confirm these findings and imply that in cases with random initialization with high probability the gain of trade is equally split between buyers and sellers.     

Horizontally Differentiated Market Makers

I analyze a model of competition between two market makers who are located at the opposite ends of the Hotelling line, both of which are also occupied by a search market. Buyers and sellers are uniformly distributed between the two market places, yet can only trade at one of them. In equilibrium, market makers net a positive profit and trade with buyers and sellers close to them, while buyers and sellers further away participate in search markets. Interestingly, a duopolistic market maker nets a larger profit than a monopoly because search markets make the quantities market makers trade strategic complements.     

二手房价格评估系统设计与研究

针对二手房交易过程中普遍存在的买卖双方信息不对称的问题,设计了一套基于B/S层次化结构的二手房价格评估系统。该系统首先通过网络爬虫从二手房网站收集公开的实时性数据信息,随后对这些数据进行预处理并建立层级化数据库。随后通过非参数回归算法对二手房价格进行评估。实验证明,本系统能够为购房者提供综合、直观的二手房趋势信息,并进行较为准确的估价。对于购房者以及售房者的决策都具有重要的参考价值。     

Intermediated surge pricing

Although Uber and Lyft are known for their flexible “surge pricing,” they are surprisingly rigid in another way: each firm takes a constant percentage of passenger fare whether or not there is a surge. In this paper, I investigate the possible reasons for, and the impact of, this rigidity. I study a market in which a profit‐maximizing intermediary facilitates trade between buyers and sellers. The intermediary sets prices for buyers and sellers, and keeps the difference as her fee. Optimal prices increase when demand increases, that is, shifts right. If a demand increase is due to an increase in the number of ex ante symmetric buyers, then the intermediary's optimal percent fee decreases. If, instead, a demand increase is due to a reduction in the elasticity of demand, then the intermediary's optimal percent fee increases. In either case, if the intermediary keeps a constant percent fee regardless of shifts in demand, as is the case with Uber and Lyft, then surge pricing (i.e., the ratio of price during high demand to price during low demand) is amplified on one side of the market and diminished on the other side.     

Countervailing power? Collusion in markets with decentralized trade

We consider the collective incentives of buyers and sellers to form cartels in markets with decentralized trade and pairwise bargaining. Cartels are coalitions of buyers or sellers that limit market participation and compensate inactive members for their abstention. In stable market outcomes, cartels set Nash equilibrium quantities and cartel memberships are immune to deviations. The set of stable market outcomes is non-empty and its full characterization is provided. Stable market outcomes are of two types: (i) at least one cartel restrains trade and market participation is balanced; (ii) only one cartel is active and it reduces trade slightly below the opponent’s.     

Competition among mechanism designers in a common value environment

A competitive economy is studied in which sellers offer alternative direct mechanisms to buyers who have private information about their own private use value for the commodity being traded. In addition the commodity has a common value to all buyers, perhaps represented by the future resale value of the commodity. A competitive equilibrium in mechanisms is described. In every such equilibrium it is shown that sellers must offer mechanisms that are allocationally equivalent to English ascending price auctions. The reservation prices that sellers set are shown to be below their ex post cost of trading the commodity. Received: 24 April 1998 / Accepted: 8 March 1999     

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.     

Management consultants as improvising agents of stability

Relatively few studies have paid theoretical as well as empirical attention to what use organizations have of management consultants and their services. By studying how buyers and sellers of management consulting services describe what management consulting is and represents, this study questions common understandings in the literature, i.e., that management consultants act as agents of change or as standardizers of organizational practice around the world. It is argued that consultants can be understood as playing the role of improvisers because there is considerable uncertainty among both buyers and sellers as to what use organizations really have of them. Playing a recognizable, yet indefinite role based on an institutionalized foundation, in both discourse and practice, of what actors such as consultants are supposed to do in certain situations, helps client organizations to reduce the uncertainty experienced. The conclusion is that management consultants can therefore be understood as agents of stability rather than agents of change.     

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.     

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.     

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.