Spectrum auction design: Simple auctions for complex sales

Following the successful PCS Auction conducted by the US Federal Communications Commission in 1994, auctions have replaced traditional ways of allocating valuable radio spectrum. Spectrum auctions have raised hundreds of billion dollars worldwide and have become a role model for market-based approaches in the public and private sectors. The PCS spectrum was sold via a simultaneous multi-round auction, which forces bidders to compete for licenses individually even though they typically value certain combinations. This exposes bidders to risk when they bid aggressively for a desired combination but end up winning an inferior subset. Foreseeing this possibility, bidders may act cautiously with adverse effects for revenue and efficiency. Combinatorial auctions allow for bids on combinations of licenses and thus hold the promise of improved performance. Recently, a number of countries worldwide have switched to the combinatorial clock auction to sell spectrum. This two-stage auction uses a core-selecting payment rule. The number of possible packages a bidder can submit grows exponentially with the number of licenses, which adds complexity to the auction. For larger auctions with dozens of licenses bidders cannot be expected to reveal all their valuations during such an auction. We analyze the impact of two main design choices on efficiency and revenue: simple “compact” bid languages versus complex “fully expressive” bid languages and simple “pay-as-bid” payment rules versus complex “core-selecting” payment rules. We consider these design choices both for ascending and sealed-bid formats. We find that simplicity of the bid language has a substantial positive impact on the auction?s efficiency and simplicity of the payment rule has as a substantial positive impact on the auction?s revenue. The currently popular combinatorial clock auction, which uses a complex bid language and payment rule, achieves the lowest efficiency and revenue among all treatment combinations.     

Raising rivals’ cost in multi-unit auctions

The objective many telecom regulators want to achieve when they decide to auction spectrum is that acquiring firms pay a market price (based on the opportunity cost principle). The simultaneous ascending auction may fail in this respect, as it provides bidders with an opportunity to engage in strategic demand reduction. This paper asks whether the combinatorial clock auction (CCA) fares better in this respect. We show that the answer to this question depends on the objectives bidders have. If bidders have only the slightest preference to raise rivals’ cost, they will use the opportunities the CCA provides them to engage in strategic demand expansion. This is even the case when the clock phase ends with excess demand.     

Last-Minute Bidding in Sequential Auctions with Unobserved, Stochastic Entry

Using a dataset of calculator auctions on eBay, we first show that last-minute bidding is not merely the result of bidders’ going to the next-to-close auction. Instead, bidding is concentrated at the end of the period in which the auction is the next to close, suggesting the existence of strategic last-minute bidding. Then, we model repeated, ascending price auctions for homogeneous goods with unobserved, stochastic entry. We show that the dynamic game has a pure-strategy symmetric equilibrium in which entrants always reveal themselves by bidding in the auction in which they arrive, and bidding occurs at the last minute.     

On-line spectrum auctions in TV white spaces for supporting mobile services—A practical manual

This paper considers an approach for dynamic short-term spectrum leasing in TV white spaces (TVWS) using an on-line auction. The secondary spectrum market discussed here is organized by a central entity called the spectrum broker. The auctioned spectrum appears in blocks of available DVB-T channels with some transmit power constraints set-up to protect the primary users (DVB-T receivers). The bidders are institutional spectrum operators (telecommunication companies or service providers), operating in a given area. These players are characterized by heterogeneous demands concerning the spectrum bandwidth, the operation period with temporarily-exclusive rights for using the spectrum and the transmit power needed for successful transmission. Thus, the auctioned objects are non-identical and present different value for different players. Two auction models are proposed. The first one is the simultaneous auction in time domain and combinatorial in frequency and power dimension. The second proposed auction is fully combinatorial. Simulations results are also provided showing effectiveness of the analyzed auctions (high spectrum utilization ratio) and relation between the players’ satisfaction, their spectrum valuation and varying competition. Finally the guidelines concerning the spectrum auctions in TVWS for the policy makers are proposed.     

A Dynamic Model of Auctions with Buy‐It‐Now: Theory and Evidence

In the ascending‐price auctions with Yahoo!‐type buy‐it‐now (BIN), we characterize and derive the closed‐form solution for the optimal bidding strategy of the bidders and the optimal BIN price of the seller when they are both risk‐averse. The seller is shown to be strictly better off with the BIN option, while the bidders are better off only when their valuation is high enough. The theory also implies that the expected transaction price is higher in an auction with an optimal BIN price than one without a BIN option. This prediction is confirmed by our data collected from Taiwan's Yahoo! auctions.     

Polish experience from first-ever spectrum auction

The Polish 4G spectrum auction was a watershed event for the Polish telecommunications market. For the first time in history, the Office of Electronic Communications decided to award spectrum by using an auction process. Polish regulators implemented a simultaneous multiple-round ascending-bid auction, which was widely used worldwide for selling spectrum. The process leading to the auction and the auction itself was lengthy and eventful. Due to the wrong auction design, the auction dragged on indefinitely, causing a delay in spectrum distribution. The auction ended only as a result of the government's intervention, after 8 months (513 rounds) of bidding that raised revenue of over PLN 9 billion (over EUR 2 billion). This paper describes in detail the rules of the Polish 4G auction, analyses bidding behaviour and auction dynamics of the crucial phases of auctions, and presents the final outcomes. It also draws lessons that could help policy makers in Poland and other countries in auction design.     

Auctions with quantity externalities and endogenous supply

This paper studies the design of license auctions when the number of licenses allocated in the auction determines structure of the post-auction market. I first show that a sequence of conditional reserve prices that specify minimum acceptable bid at each supply level can be used to determine supply endogenously. Then I construct a static auction called multi-dimensional uniform-price auction and a dynamic auction called Walrasian clock auction that allow the auctioneer to condition reserve price on supply and allow bidders to condition bids on supply. I show that both proposed auctions can implement the efficient market structure that maximizes total surplus in the post-auction market in a dominant strategy equilibrium. I next characterize the optimal auction and show that the two proposed auctions can yield the optimal revenue under a sequence of optimal reserve prices.     

Effects of Minimum Bid Increments in Internet Auctions: Evidence from a Field Experiment

I study the role of minimum bid increments (MBI) in internet auctions using natural field experiment data from a Finnish online auction site Huuto.net. Internet auctions are typically viewed as second‐price, implying truthful bidding. However, due to the presence of the MBI, equilibrium bidding behavior involves bid shading. I sell otherwise identical gift cards while varying the MBI and test between truthful bidding and bid shading. Truthful bidding is rejected. Consistently with equilibrium behavior, bid shading increases as the MBI increases. This implies that real‐world bidders are capable of reacting rationally even to seemingly small variations in their strategic environment.     

Secret reserve prices in first-price auctions

This article offers a theoretical explanation for the use of secret reserve prices in auctions. I study first-price auctions with and without secret reserve price in an independent private values environment with risk-neutral buyers and a seller who cares at least minimally about risk. The seller can fix the auction rules either before or after she learns her reservation value. Fixing the rules early and keeping the right to set a secret reserve price can be strictly optimal. Moreover, I describe the relation of using a secret reserve price to phantom bidding and non-commitment to sell.     

Optimal reserve prices in sealed-bid auctions with reference effects

The reference effect and loss aversion are incorporated into the buyer’s utility in the symmetric independent private value models of sealed-bid auctions. The buyer’s equilibrium bidding strategy and the seller’s optimal reserve price are derived for the first-price and second-price sealed-bid auctions. In both auction mechanisms, the seller’s optimal reserve price and expected revenue are increasing in the reference point. We compare the seller’s expected revenues as well as the optimal reserve prices in the two auctions. The results show that the seller will set a higher optimal reserve price but obtain lower optimal expected revenue in the second-price auction compared to the first-price auction. Further, we extend the model to the gain-seeking case, and endogenize the reference point as the ex-ante expected price of the item in equilibrium. In contrast to the loss-averse case, the seller will set a lower optimal reserve price but obtain higher optimal expected revenue in the second-price auction compared to the first-price auction if the buyers are gain-seeking. With an endogenous reference point, similar results are obtained in terms of revenue comparison between the two auctions.     

Bids for the UMTS system: An empirical evaluation of the Italian case

The aim of this paper is to analyze the licensing of the telecommunication spectrum as a public good and the search for equilibrium prices through bilateral bargaining and multilateral bidding. It develops a general model of price setting under dynamic uncertainty and applies it to the Italian auction for Universal Mobile Telecommunications System (UMTS). The empirical application shows that the model can be used both to determine the base price as well as other desirable characteristics to organize an auction and to better understand, after the auction is closed, what really happened in terms of the critical factors involved. After recalling some basic concepts on spectrum rights and reviewing the general experience with UMTS auctions in Europe, the formal model and its application are presented. The results confirm certain views on the Italian auction, which are widely shared but were never tested before, namely that: (i) given the initial price, the number of licenses offered for the bidding should have been fewer, or alternatively, (ii) given the number of licenses, the base price should have been higher and (iii) the main bidder underpaid for the license. The model also allows us to quantify the bidders’ reservation price and the State and the bidders’ implicit bargaining powers.     

Uncertainty and Auction Outcomes: Evidence from Used Car Actions

I study the sequence of bidding in an open-outcry English auction to examine how uncertainty affects auction outcomes. I do this by analyzing a data set that was collected from a series of public auctions of used cars in New Jersey. I conjecture that the uncertainty is related to the auction’s progress and demonstrate that, empirically, an increase in the uncertainty is associated with an increase in the number of rounds that is required to sell an object and with a reduction in the ratio of the selling price to the presale estimate.     

Sorry Winners

Bidders who receive both “common-value” and “private-value” signals about the value of an auction prize cannot fully infer their opponents’ information from the bidding. So bidders may overestimate the value of the prize and, subsequently, regret winning. When multiple objects are on sale, bidding in an auction provides information relevant to the other auctions, and sequential auctions are more vulnerable to overpayment and winners’ regret than are simultaneous auctions. With information inequality among bidders, the seller’s revenue is influenced by two contrasting effects. On the one hand, simultaneous auctions reduce the winner’s curse of less informed bidders and allow them to bid more aggressively. On the other hand, sequential auctions induce less informed bidders to bid more aggressively in early auctions to acquire information.      

Low price equilibrium in multi-unit auctions: the GSM spectrum auction in Germany

The second–generation (GSM) spectrum auction in Germany is probably the most clear cut example of a low price outcome in a simultaneous ascending-bid multi-unit auction. The present paper gives an account of the events, describes the auction rules and market conditions, and provides a game theoretic explanation of low price equilibrium in simultaneous, ascending-bid multi-unit auctions. In particular, it is shown that in the unique equilibrium that survives iterated elimination of dominated strategies, the efficient allocation is reached at minimum bids.     

The effect of competition on eBay

I examine the effect of competition on eBay Motors. I specify a simple model of auction choice and show that the expected transaction price falls with an increase in the number of competitors. I then test for this effect using data from 5,500 auctions for Chevrolet Corvettes. To address potential endogeneity of the level of competition, I introduce an instrument which takes advantage of the unique features of eBay. Results indicate that an additional competitor leads to a 6% reduction in the final transacted price ($960 for the average car). Further, I provide evidence that this effect is due to the thinning of the bidder market rather than dynamic bidding.     

How to Set Minimum Acceptable Bids, with an Application to Real Estate Auctions

In a general auction model with affiliated signals, common components to valuations and endogenous entry, we compute the equilibrium bidding strategies and outcomes, and derive a lower bound on the optimal reserve price. This lower bound can be computed using data on past auctions combined with information about the subsequent sales prices of unsold goods. We illustrate how to compute the lower bound using data from real estate auctions.     

Auctions with bid credits and resale

Bid credits favoring subsets of bidders are routinely imposed on auctions and procurement auctions. These bid credits result in inefficient auction outcomes, which create pressure for post-auction resale or, in a procurement context, for subcontracting. We show that the presence of resale, in turn, affects bidding strategies in such a way that auction outcomes are more likely to be inefficient and less informative, making it harder for resale to correct inefficiencies. The negative effects of bid credits and resale can be mitigated through direct restrictions on resale, tight caps on credits, reserve prices, anonymous bidding, and enhanced competition.     

A combinatorial auction to sell TV broadcasting rights in league sports

The centralized sale of TV broadcasting rights in league sports constitutes a cartel which in many European countries is allowed only if it complies with certain conditions set by competition authorities. Two of the most important conditions are: i) partial unbundling, i.e. the rights must be unbundled into several separate packages; and ii) the no-single-buyer rule, i.e. the packages must be sold to different broadcasters. This article shows how a combinatorial auction can be employed to sell broadcasting rights allocating them endogenously based on the broadcasters’ bids and, thus, without requiring the seller to pre-determine the packages of such rights. This feature can address various competition policy issues, including facilitating market entry and preventing coordination among bidders. Also, a combinatorial auction has the potential to achieve higher levels of allocative efficiency and higher revenue levels compared to auctions with pre-determined packages of broadcasting rights.     

On Strategic Quantity Bidding in Multiple Unit Auctions

Standard studies of multiple unit auctions generally overlook the strategic role of bidders' quantity decisions. Using a simple equilibrium model of bidding I analyze bidders' incentives to choose quantities in discriminatory and competitive auctions. The main result is that bidders have a stronger strategic incentive to bid for fewer units in competitive auctions. Since under competition a bidder pays the lowest accepted price for each unit she gets, she may benefit from dropping her quantity to let lower-valuing bidders enter the set of winners. This prediction is consistent with empirical observations from foreign currency and spectrum auctions.     

First‐Price Sealed‐Bid Tender versus English Open Auction: Evidence from Land Auctions

This article compares whether the first‐price sealed‐bid tender or the ascending English open auction generates higher revenue for the seller. Using a unique set of data for land sales and accounting for the presence of an endogenous discrete mechanism choice variable, our results show that the first‐price sealed‐bid tender generates a lower land price, in the range of 1.2–9.6%, than the English open auction. Our results validate the theoretical prediction that open auctions result in higher prices because bidders can infer other bidders’ information by observing their bids in the common value auction paradigm.