Jonathan W. Williams

Does Multimarket Contact Facilitate Tacit Collusion? Inference on Conduct Parameters in the Airline Industry

We show that multimarket contact facilitates tacit collusion in the US airline industry using two complementary approaches. First, we show that the more extensive is the overlap in the markets that the two firms serve, i) the more firms internalize the effect of their pricing decisions on the profit of their competitors by reducing the discrepancy in their prices, and ii) the greater the rigidity of prices over time. Next, we develop a flexible model of oligopolistic behavior, where conduct parameters are modeled as functions of multimarket contact. We find i) carriers with little multimarket contact do not cooperate in setting fares, while carriers serving many markets simultaneously sustain almost perfect coordination; ii) cross-price elasticities play a crucial role in determining the impact of multimarket contact on collusive behavior and equilibrium fares; iii) marginal changes in multimarket contact matter only at low or moderate levels of contact; iv) assuming that firms behave as Bertrand-Nash competitors leads to biased estimates of marginal costs.

Can Financial Markets Inform Operational Improvement Efforts? Evidence from the Airline Industry

We investigate whether stock price movements can inform operations managers as to where they should focus improvement efforts. We examine how unexpected performance along several dimensions of service quality---on-time performance, long delays and cancellations, lost bags, and denied boardings---impacts contemporaneous stock returns. Prior research suggests that airlines buffer their flight schedules and engage in expensive employee incentive programs to increase the likelihood of on-time arrival. We find that only long delays are penalized by the market, and we identify a number of carrier-specific factors that alter the financial impact of long delays. We find that the penalty a carrier faces for long delays is significantly higher if it operates a high percentage of short-haul or connecting flights, or if its competitors incur fewer long delays in the same time period. Our findings suggest that developing ways to curtail long delays is a useful future research area.

Barriers to Entry in the Airline Industry: A Multidimensional Regression-Discontinuity Analysis of AIR-21

We investigate the success of legislation aimed at increasing competition at highly concentrated U.S. airports, mainly by forcing these airports to increase the availability of scarce facilities. We use a multidimensional regression-discontinuity approach to exploit a sharp discontinuity in the law’s implementation and identify its effects. We find that fares decrease by 13.4% (20.2%) in markets with one (both) end point(s) covered. Approximately half of the decline is driven by the entry of low-cost carriers. We find little evidence that the fare declines were accompanied by a diminished quality of service, and passenger volumes increased, which suggests the legislation improved consumer welfare.

Capacity Investments, Exclusionary Behavior, and Welfare: A Dynamic Model of Competition in the Airline Industry

This paper uses unique data on access to airport facilities to study the strategic entry, exit, and capacity decisions of firms in the US airline industry. I estimate a dynamic equilibrium model in which forward-looking firms invest in seating capacity and play a capacity-constrained pricing game. I find that the intensity of competition depends directly on the characteristics and identity of the incumbent fi rm. In particular, dominant hub carriers aggressively invest in capacity following entry by low-cost carriers, providing a commitment to price aggressively in future periods. In doing so, the hub carrier can substantially increase the likelihood of exit by the targeted rm. The resulting reduction in the level of competition reduces consumer welfare relative to an environment in which anti-trust authorities can eliminate such exclusionary behavior.

Robust Scheduling Practices in the U.S. Airline Industry: Costs, Returns, and Inefficiencies.

Airlines use robust scheduling to mitigate the impact of unforeseeable disruptions on profits. We examine how effectively three common practices—flexibility to swap aircraft, flexibility to reassign gates, and scheduled aircraft downtime—accomplish this goal. We first estimate a multiple-input, multiple-outcome production frontier, which defines the attainable set of outcomes from given inputs. We then recover unobserved input costs and calculate how expenditure on inputs affects outcomes and revenues. We find that the per-dollar return from expenditure on gates, or more effective management of existing gate capacity, is three times larger than the per-dollar returns from other inputs. Next, we use the estimated trade-offs faced by carriers along the frontier to measure the value to carriers of reducing delays. Finally, we calculate the improvement in carriers’ outcomes and profits if their operational inefficiencies are eliminated. On average, we estimate that operational inefficiencies cost carriers about

Trends in Private Patent Costs and Rents for Publicly-Traded United States Firms

1.7 billion in revenue annually. This paper was accepted by Serguei Netessine, operations management .

Network Structure and Consolidation in the U.S. Airline Industry, 1990-2015

We use detailed data to estimate the private costs and private rents of United States patents for publicly-traded firms. In analyzing costs, we first introduce a novel theoretical model to interpret our estimates. We then combine lawsuit data from Derwent Litalert with non-practicing entity (NPE) lawsuits collected by Patent Freedom, and use an event-study approach to estimate losses suffered by alleged infringers during 1984-2009. To estimate rents, we combine patent data from the USPTO and EPO with financial data from COMPUSTAT, and use market-value regressions to estimate the value of patent rents for publicly-traded US firms during 1979-2002. We find that private costs exceed private rents during 1999-2000 and the trend in costs is sharply higher. Costs also exceed forecasts of rents for 2005-09. A surge in the number of NPE lawsuits contributes to the increase in the gap.

Two Screening Tests for Tacit Collusion: Evidence from the Airline Industry

We study the effect of consolidation on airline network connectivity using three measures of centrality from graph theory: Degree, Closeness, and Betweenness. Changes in these measures from 1990 to 2015 imply: i) the average airport services a greater proportion of possible routes, ii) the average origin airport is fewer stops away from any given destination, and iii) the average hub is less often along the shortest route between two other airports. Yet, we find the trend toward greater connectivity in the national network structure is largely unaffected by consolidation, in the form of mergers and codeshare agreements, during this period.

Effects of Mergers and Divestitures on Airline Fares

Abstract We formulate two empirical tests for collusive behavior based on the theoretical insights of Werden and Froeb (1994) and Athey, Bagwell, and Sanchirico (2004). The first predicts that colluding firms will reduce pair-wise differences in prices within a market if demand satisfies certain properties. The second predicts that colluding firms will sacrifice efficiency in production by increasing price rigidity to avoid informational costs. Using panel data from the US airline industry and fixed-effects estimation, we find that greater multimarket contact between carriers leads to pricing patterns consistent with both theoretical predictions, while code-share agreements are consistent with the second prediction.

The Tragedy of the Last Mile: Congestion Externalities in Broadband Networks

U.S. antitrust authorities have increasingly forced merging companies to divest assets as a condition for merger approval, with the goal of creating a more competitive postmerger environment. This study examined the effectiveness of this government strategy in the context of the airline industry, in which forced divestitures have occurred in recent consolidations. The study used unique data on assets critical to airport facilities that were involved in the divestitures to document the reallocation of those assets to low-cost carriers. Estimates of the impact of the divestitures on airfares were then calculated. The results show that, at the affected airports, fares for merging carriers fell by 3% and fares for nonmerging carriers fell by 1% relative to airports at which no divestiture occurred. These results provide evidence that the divestiture strategy used by antitrust authorities is effective in this setting in mitigating market power.