Lixin Ye

Deciding Between Competition and Collusion

We develop an approach to identify and test for bid rigging in procurement auctions. First, we introduce a general auction model with asymmetric bidders. Second, we study the problem of identification in our model. We state a set of conditions that are both necessary and sufficient for a distribution of bids to be generated by a model with competitive bidding. Third, we discuss how to elicit a prior distribution over a firms structural cost parameters from industry experts. Given this prior distribution, we use Bayess theorem to compare competitive and collusive models of industry equilibrium. Finally, we apply our methodology to a data set of bidding by construction firms in the Midwest. The techniques we propose are not computationally demanding, use flexible functional forms, and can be programmed using most standard statistical packages.

Indicative bidding and a theory of two-stage auctions

Motivated by the practice of indicative bidding, which is commonly used in sales of complex and valuable assets, this paper develops a theory of two-stage auctions based on the assumption that learning valuation is costly. In various cases that characterize what can be learned in the due diligence stage, we show that no symmetric increasing equilibrium exists and hence efficient entry cannot be guaranteed under the current design of indicative bidding. However, by introducing auctions of entry rights with binding first-round bids, we show that efficient entry can be induced under certain conditions. We also show that optimal auctions are typically characterized by a limited number of final bidders, which justifies the general practice of conducting two-stage auctions in environments with costly entry.

Quality Disclosure and Competition

We analyze costly quality disclosure with horizontally differentiated products under duopoly and a cartel, and characterize the effect of competition on disclosure and welfare. We show that expected disclosure is higher under a cartel than under duopoly, and the welfare comparison depends on the level of disclosure cost: when the disclosure cost is low, welfare is higher under a cartel than duopoly, but when the disclosure cost is high, welfare is higher under duopoly. In either market structure, disclosure is excessive in terms of total surplus, but insufficient in terms of consumer surplus.

Reserve price signaling

Abstract In a general auction model in which bidders’ signals are affiliated, we characterize the unique separating equilibrium in which the seller can use reserve prices to credibly signal her private information. When the buyers’ signals are independent, the optimal reserve price is shown to be increasing in the number of bidders under certain conditions. We also demonstrate that the probability that the item is sold at the reserve price can increase as the number of bidders increases, which indicates a more central role for reserve prices than perceived in the standard auction models.

Indicative bidding: An experimental analysis

Indicative bidding is a practice commonly used in sales of complex and very expensive assets. Theoretical analysis shows that efficient entry is not guaranteed under indicative bidding, since there is no equilibrium in which more qualified bidders are more likely to be selected for the final sale. Furthermore, there exist alternative bid procedures that, in theory at least, guarantee 100% efficiency and higher revenue for the seller. We employ experiments to compare actual performance between indicative bidding and one of these alternative procedures. The data shows that indicative bidding performs as well as the alternative procedure in terms of entry efficiency, while having other characteristics that favor it over the alternative procedure. Our results provide an explanation for the widespread use of indicative bidding despite the potential problem identified in the equilibrium analysis.

Auctions with entry and resale

We study how resale affects auctions with costly entry in a model where bidders possess two-dimensional private information signals: entry costs and valuations. We establish the existence of symmetric entry equilibrium and identify sufficient conditions under which the equilibrium is unique. Our analysis suggests that the opportunity of resale affects both entry and bidding, and, in particular, it induces motivation for speculative entry and resale hunting abstentions. Our numerical results suggest that while expected entry is higher when resale is allowed, the effects of resale on expected revenue and efficiency are both ambiguous.

Trademark Sales, Entry, and the Value of Reputation

We develop an infinite-horizon, overlapping-generations model of reputation in which consumers base willingness to pay for agent services on past performance summarized by a trademark. We show that when trademarks can be sold, successful firms capture the full value of their reputations upon sale but receive smaller premia for good performance while active as service providers. With discounting, all agents are worse off with trademark trade. Taking entry cost into account, we show that trademark trade typically reduces entry. When entry costs are high, welfare is increased by prohibiting such trade.

Assessing the potential for spectrum sharing between communications and radar systems in the L-band portion of the RF spectrum allocated to radar

The theoretical feasibility of dynamic spectrum sharing between rotating radar and wireless communications systems in L-band is investigated via numerical analyses in this paper. The temporal variations of interference power due to periodic rotations of radar antenna and the interference attenuation resulting from frequency separation can substantially contribute to the link loss. Consequently, even in the scenario where cellular devices are fairly close to radar, there still will be periods of time when the link loss is high enough such that cellular systems can take opportunity to transmit while without interfering with radar. Numerical results show that in the scenario where spectrum sharing between a single cell and single rotating radar is considered, although with some interruptions, the communications system can achieve its data rate limit within a range that is a few kilometers away from the radar.

Efficient and optimal mechanisms with private information acquisition costs

In auctions with private information acquisition costs, we completely characterize (socially) efficient and (revenue) optimal two-stage mechanisms, with the first stage being an entry right allocation mechanism and the second stage being a traditional private good provision mechanism. Both efficiency and revenue optimality require that the second-stage selling mechanism be ex post efficient and the number of entry slots be endogenously determined. We show that both efficient and optimal entry can be truthfully implemented in dominant strategies, and can also be implemented via all-pay, though not uniform-price or discriminatory-price, auctions.

On spectrum sharing between communications and air traffic control radar systems

The feasibility of dynamic spectrum sharing between air traffic control radar and wireless communications systems is investigated via a numerical simulation. The temporal variations of interference power due to periodic rotations of the radar antenna and the interference attenuation resulting from frequency separation can substantially contribute to link loss. Consequently, even in the scenario where cellular devices are located close to the radar, there still will be periods of time when the mutual interference is low enough such that cellular systems can take opportunity to transmit. Numerical results show that in the scenario where spectrum sharing between a single cell and the single rotating radar is considered, although both systems are subject to certain levels of performance degradation due to the impact each has on the other, the design of efficient spectral sharing mechanisms is still possible.