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Germán Gutiérrez and Thomas Philippon have released a major rewrite of their paper comparing the U.S. and EU competitive environments. 

Although the NBER website provides an enticing title — “How European Markets Became Free: A Study of Institutional Drift” — the paper itself has a much more yawn-inducing title: “How EU Markets Became More Competitive Than US Markets: A Study of Institutional Drift.”

Having already critiqued the original paper at length (here and here), I wouldn’t normally take much interest in the do-over. However, in a recent episode of Tyler Cowen’s podcast, Jason Furman gave a shout out to Philippon’s work on increasing concentration. So, I thought it might be worth a review.

As with the original, the paper begins with a conclusion: The EU appears to be more competitive than the U.S. The authors then concoct a theory to explain their conclusion. The theory’s a bit janky, but it goes something like this:

  • Because of lobbying pressure and regulatory capture, an individual country will enforce competition policy at a suboptimal level.
  • Because of competing interests among different countries, a “supra-national” body will be more independent and better able to foster pro-competitive policies and to engage in more vigorous enforcement of competition policy.
  • The EU’s supra-national body and its Directorate-General for Competition is more independent than the U.S. Department of Justice and Federal Trade Commission.
  • Therefore, their model explains why the EU is more competitive than the U.S. Q.E.D.

If you’re looking for what this has to do with “institutional drift,” don’t bother. The term only shows up in the title.

The original paper provided evidence from 12 separate “markets,” that they say demonstrated their conclusion about EU vs. U.S. competitiveness. These weren’t really “markets” in the competition policy sense, they were just broad industry categories, such as health, information, trade, and professional services (actually “other business sector services”). 

As pointed out in one of my earlier critiques, In all but one of these industries, the 8-firm concentration ratios for the U.S. and the EU are below 40 percent and the HHI measures reported in the original paper are at levels that most observers would presume to be competitive. 

Sending their original markets to drift in the appendices, Gutiérrez and Philippon’s revised paper focuses its attention on two markets — telecommunications and airlines — to highlight their claims that EU markets are more competitive than the U.S. First, telecoms:

To be more concrete, consider the Telecom industry and the entry of the French Telecom company Free Mobile. Until 2011, the French mobile industry was an oligopoly with three large historical incumbents and weak competition. … Free obtained its 4G license in 2011 and entered the market with a plan of unlimited talk, messaging and data for €20. Within six months, the incumbents Orange, SFR and Bouygues had reacted by launching their own discount brands and by offering €20 contracts as well. … The relative price decline was 40%: France went from being 15% more expensive than the US [in 2011] to being 25% cheaper in about two years [in 2013].

While this is an interesting story about how entry can increase competition, the story of a single firm entering a market in a single country is hardly evidence that the EU as a whole is more competitive than the U.S.

What Gutiérrez and Philippon don’t report is that from 2013 to 2019, prices declined by 12% in the U.S. and only 8% in France. In the EU as a whole, prices decreased by only 5% over the years 2013-2019.

Gutiérrez and Philippon’s passenger airline story is even weaker. Because airline prices don’t fit their narrative, they argue that increasing airline profits are evidence that the U.S. is less competitive than the EU. 

The picture above is from Figure 5 of their paper (“Air Transportation Profits and Concentration, EU vs US”). They claim that the “rise in US concentration and profits aligns closely with a controversial merger wave,” with the vertical line in the figure marking the Delta-Northwest merger.

Sure, profitability among U.S. firms increased. But, before the “merger wave,” profits were negative. Perhaps predatory pricing is pro-competitive after all.

Where Gutiérrez and Philippon really fumble is with airline pricing. Since the merger wave that pulled the U.S. airline industry out of insolvency, ticket prices (as measured by the Consumer Price Index), have decreased by 6%. In France, prices increased by 4% and in the EU, prices increased by 30%. 

The paper relies more heavily on eyeballing graphs than statistical analysis, but something about Table 2 caught my attention — the R-squared statistics. First, they’re all over the place. But, look at column (1): A perfect 1.00 R-squared. Could it be that Gutiérrez and Philippon’s statistical model has (almost) as many parameters as variables?

Notice that all the regressions with an R-squared of 0.9 or higher include country fixed effects. The two regressions with R-squareds of 0.95 and 0.96 also include country-industry fixed effects. It’s very possible that the regressions results are driven entirely by idiosyncratic differences among countries and industries. 

Gutiérrez and Philippon provide no interpretation for their results in Table 2, but it seems to work like this, using column (1): A 10% increase in the 4-firm concentration ratio (which is different from a 10 percentage point increase), would be associated with a 1.8% increase in prices four years later. So, an increase in CR4 from 20% to 22% (or an increase from 60% to 66%) would be associated with a 1.8% increase in prices over four years, or about 0.4% a year. On the one hand, I just don’t buy it. On the other hand, the effect is so small that it seems economically insignificant. 

I’m sure Gutiérrez and Philippon have put a lot of time into this paper and its revision. But there’s an old saying that the best thing about banging your head against the wall is that it feels so good when it stops. Perhaps, it’s time to stop with this paper and let it “drift” into obscurity.

[TOTM: The following is part of a blog series by TOTM guests and authors on the law, economics, and policy of the ongoing COVID-19 pandemic. The entire series of posts is available here.

This post is authored by Brent Skorup, (Senior Research Fellow, Mercatus Center, George Mason University).]

One of the most visible economic effects of the COVID-19 spread is the decrease in airline customers. Alec Stapp alerted me to the recent outrage over “ghost flights,” where airlines fly nearly empty planes to maintain their “slots.” 

The airline industry is unfortunately in economic freefall as governments prohibit and travelers pull back on air travel. When the health and industry crises pass, lawmakers will have an opportunity to evaluate the mistakes of the past when it comes to airport congestion and airspace design.

This issue of ghost flights pops up occasionally and offers a lesson in the problems with government rationing of public resources. In this case, the public resource are airport slots: designated times, say, 15 or 30 minutes, a plane may takeoff or land at an airport. (Last week US and EU regulators temporarily waived the use-it-or-lose it rule for slots to mitigate the embarrassing cost and environmental damage caused by forcing airlines to fly empty planes.)

The slots at major hubs at peak times of day are extremely scarce–there’s only so many hours in a day. Today, slot assignment are administratively rationed in a way that favors large, incumbent airlines. As the Wall Street Journal summarized last year,

For decades, airlines have largely divided runway access between themselves at twice-yearly meetings run by the IATA (an airline trade group).

Airport slots are property. They’re valuable. They can be defined, partitioned, leased, put up as collateral, and, in the US, they can be sold and transferred within or between airports.

You just can’t call slots property. Many lawmakers, regulators, and airline representatives refuse to acknowledge the obvious. Stating that slots are valuable public property would make clear the anticompetitive waste that the 40-year slot assignment experiment generates. 

Like many government programs, the slot rationing began in the US as a temporary program decades ago as a response to congestion at New York airports. Slots are currently used to ration access at LGA, JFK, and DCA. And while they don’t use formal slot rationing, the FAA also rations access at four other busy airports: ORD, Newark, LAX, and SFO.

Fortunately, cracks are starting to form. In 2008, at the tailend of the Bush administration, the FAA proposed to auction some slots in New York City’s three airports. The plan was delayed by litigation from incumbent airlines and an adverse finding from the GAO. With a change in administration, the Obama FAA rescinded the plan in 2009.

Before the Obama FAA recission, the mask slipped a bit in the GAO’s criticism of the slot auction plan: 

FAA’s argument that slots are property proves too much—it suggests that the agency has been improperly giving away potentially millions of dollars of federal property, for no compensation, since it created the slot system in 1968.


Though the GAO helped scuttle the plan, the damage has been done. The idea has now entered public policy discourse: giving away valuable public property is precisely what’s going on. 

The implicit was made explicit in 2011 when, despite spiking the Bush FAA plan, the Obama FAA auctioned two dozen high-value slots. (The reversal and lack of controversy is puzzling to me.) Delta and US Airways wanted to swap some 160 slots at New York and DC airports. As a condition of the mega-swap, the Obama FAA required they divest 24 slots at those popular airports, which the agency auctioned to new entrants. Seven low-fare airlines bid in the auction and Jetblue and WestJet won the divested slots, paying about $90 million combined

The older fictions are rapidly eroding. There is an active secondary market in slots in some nations and when prices are released it becomes clear that the legacy rationing amounts to public property setasides to insiders. In 2016 it leaked, for instance, that an airline paid £58 million for a pair of take-off and landing slots at Heathrow. Other slot sales are in the tens of millions of dollars.

The 2011 FAA auctions and the loosening of rules globally around slot sales signal that the competition benefits from slot markets are too obvious to ignore. Competition from new entry drives down airfare and increases the number of flights.

For instance, a few months ago researchers used a booking app to scour 50 trillion flight itineraries to see new entrants’ effect on airline ticket prices between 2017 and 2019. As the Wall Street Journal reported, the entry of a low-fare carrier reduced ticket prices by 17% on average. The bigger effect was on output–new entry led to a 30% YoY increase in flights.

It’s becoming harder to justify the legacy view, which allow incumbent airlines to dominate the slot allocations via international conferences and national regulations that require “grandfather” slot usage. In a separate article last year, the Wall Street Journal reported that airlines are reluctantly ceding more power to airports in the assignment of slots. This is another signal in the long-running tug-of-war between airports and airlines. Airports generally want to open slots for new competitors–incumbent airlines do not.

The reason for the change of heart? The Journal says,

Airlines and airports reached the deal in part because of concerns governments should start to sell slots.

Gulp. Ghost flights are a government failure but a rational response to governments withholding the benefits of property from airlines. The slot rationing system encourages flying uneconomical flights, smaller planes, and excess carbon emissions. The COVID-19 crisis allowed the public a glimpse at the dysfunctional system. It won’t be easy, but aviation regulators worldwide need to assess slots policy and airspace access before the administrative rationing system spreads to the emerging urban air mobility and drone delivery markets.

Wall Street Journal commentator, Greg Ip, reviews Thomas Philippon’s forthcoming book, The Great Reversal: How America Gave Up On Free Markets. Ip describes a “growing mountain” of research on industry concentration in the U.S. and reports that Philippon concludes competition has declined over time, harming U.S. consumers.

In one example, Philippon points to air travel. He notes that concentration in the U.S. has increased rapidly—spiking since the Great Recession—while concentration in the EU has increased modestly. At the same time, Ip reports “U.S. airlines are now far more profitable than their European counterparts.” (Although it’s debatable whether a five percentage point difference in net profit margin is “far more profitable”). 

On first impression, the figures fit nicely with the populist antitrust narrative: As concentration in the U.S. grew, so did profit margins. Closer inspection raises some questions, however. 

For example, the U.S. airline industry had a negative net profit margin in each of the years prior to the spike in concentration. While negative profits may be good for consumers, it would be a stretch to argue that long-run losses are good for competition as a whole. At some point one or more of the money losing firms is going to pull the ripcord. Which raises the issue of causation.

Just looking at the figures from the WSJ article, one could argue that rather than concentration driving profit margins, instead profit margins are driving concentration. Indeed, textbook IO economics would indicate that in the face of losses, firms will exit until economic profit equals zero. Paraphrasing Alfred Marshall, “Which blade of the scissors is doing the cutting?”

While the concentration and profits story fits the antitrust populist narrative, other observations run contrary to Philippon’s conclusion. For example, airline prices, as measured by price indexes, show that changes in U.S. and EU airline prices have fairly closely tracked each other until 2014, when U.S. prices began dropping. Sure, airlines have instituted baggage fees, but the CPI includes taxes, fuel surcharges, airport, security, and baggage fees. It’s not obvious that U.S. consumers are worse off in the so-called era of rising concentration.

Regressing U.S. air fare price index against Philippon’s concentration information in the figure above (and controlling for general inflation) finds that if U.S. concentration in 2015 was the same as in 1995, U.S. airfares would be about 2.8% lower. That a 1,250 point increase in HHI would be associated with a 2.8% increase in prices indicates that the increased concentration in U.S. airlines has led to no significant increase in consumer prices.

Also, if consumers are truly worse off, one would expect to see a drop off or slow down in the use of air travel. An eyeballing of passenger data does not fit the populist narrative. Instead, we see airlines are carrying more passengers and consumers are paying lower prices on average.

While it’s true that low-cost airlines have shaken up air travel in the EU, the differences are not solely explained by differences in market concentration. For example, U.S. regulations prohibit foreign airlines from operating domestic flights while EU carriers compete against operators from other parts of Europe. While the WSJ’s figures tell an interesting story of concentration, prices, and profits, they do not provide a compelling case of anticompetitive conduct.

As Thom previously posted, he and I have a new paper explaining The Case for Doing Nothing About Common Ownership of Small Stakes in Competing Firms. Our paper is a response to cries from the likes of Einer Elhauge and of Eric Posner, Fiona Scott Morton, and Glen Weyl, who have called for various types of antitrust action to reign in what they claim is an “economic blockbuster” and “the major new antitrust challenge of our time,” respectively. This is the first in a series of posts that will unpack some of the issues and arguments we raise in our paper.

At issue is the growth in the incidence of common-ownership across firms within various industries. In particular, institutional investors with broad portfolios frequently report owning small stakes in a number of firms within a given industry. Although small, these stakes may still represent large block holdings relative to other investors. This intra-industry diversification, critics claim, changes the managerial objectives of corporate executives from aggressively competing to increase their own firm’s profits to tacitly colluding to increase industry-level profits instead. The reason for this change is that competition by one firm comes at a cost of profits from other firms in the industry. If investors own shares across firms, then any competitive gains in one firm’s stock are offset by competitive losses in the stocks of other firms in the investor’s portfolio. If one assumes corporate executives aim to maximize total value for their largest shareholders, then managers would have incentive to soften competition against firms with which they share common ownership. Or so the story goes (more on that in a later post.)

Elhague and Posner, et al., draw their motivation for new antitrust offenses from a handful of papers that purport to establish an empirical link between the degree of common ownership among competing firms and various measures of softened competitive behavior, including airline prices, banking fees, executive compensation, and even corporate disclosure patterns. The paper of most note, by José Azar, Martin Schmalz, and Isabel Tecu and forthcoming in the Journal of Finance, claims to identify a causal link between the degree of common ownership among airlines competing on a given route and the fares charged for flights on that route.

Measuring common ownership with MHHI

Azar, et al.’s airline paper uses a metric of industry concentration called a Modified Herfindahl–Hirschman Index, or MHHI, to measure the degree of industry concentration taking into account the cross-ownership of investors’ stakes in competing firms. The original Herfindahl–Hirschman Index (HHI) has long been used as a measure of industry concentration, debuting in the Department of Justice’s Horizontal Merger Guidelines in 1982. The HHI is calculated by squaring the market share of each firm in the industry and summing the resulting numbers.

The MHHI is rather more complicated. MHHI is composed of two parts: the HHI measuring product market concentration and the MHHI_Delta measuring the additional concentration due to common ownership. We offer a step-by-step description of the calculations and their economic rationale in an appendix to our paper. For this post, I’ll try to distill that down. The MHHI_Delta essentially has three components, each of which is measured relative to every possible competitive pairing in the market as follows:

  1. A measure of the degree of common ownership between Company A and Company -A (Not A). This is calculated by multiplying the percentage of Company A shares owned by each Investor I with the percentage of shares Investor I owns in Company -A, then summing those values across all investors in Company A. As this value increases, MHHI_Delta goes up.
  2. A measure of the degree of ownership concentration in Company A, calculated by squaring the percentage of shares owned by each Investor I and summing those numbers across investors. As this value increases, MHHI_Delta goes down.
  3. A measure of the degree of product market power exerted by Company A and Company -A, calculated by multiplying the market shares of the two firms. As this value increases, MHHI_Delta goes up.

This process is repeated and aggregated first for every pairing of Company A and each competing Company -A, then repeated again for every other company in the market relative to its competitors (e.g., Companies B and -B, Companies C and -C, etc.). Mathematically, MHHI_Delta takes the form:

where the Ss represent the firm market shares of, and Betas represent ownership shares of Investor I in, the respective companies A and -A.

As the relative concentration of cross-owning investors to all investors in Company A increases (i.e., the ratio on the right increases), managers are assumed to be more likely to soften competition with that competitor. As those two firms control more of the market, managers’ ability to tacitly collude and increase joint profits is assumed to be higher. Consequently, the empirical research assumes that as MHHI_Delta increases, we should observe less competitive behavior.

And indeed that is the “blockbuster” evidence giving rise to Elhauge’s and Posner, et al.,’s arguments  For example, Azar, et. al., calculate HHI and MHHI_Delta for every US airline market–defined either as city-pairs or departure-destination pairs–for each quarter of the 14-year time period in their study. They then regress ticket prices for each route against the HHI and the MHHI_Delta for that route, controlling for a number of other potential factors. They find that airfare prices are 3% to 7% higher due to common ownership. Other papers using the same or similar measures of common ownership concentration have likewise identified positive correlations between MHHI_Delta and their respective measures of anti-competitive behavior.

Problems with the problem and with the measure

We argue that both the theoretical argument underlying the empirical research and the empirical research itself suffer from some serious flaws. On the theoretical side, we have two concerns. First, we argue that there is a tremendous leap of faith (if not logic) in the idea that corporate executives would forgo their own self-interest and the interests of the vast majority of shareholders and soften competition simply because a small number of small stakeholders are intra-industry diversified. Second, we argue that even if managers were so inclined, it clearly is not the case that softening competition would necessarily be desirable for institutional investors that are both intra- and inter-industry diversified, since supra-competitive pricing to increase profits in one industry would decrease profits in related industries that may also be in the investors’ portfolios.

On the empirical side, we have concerns both with the data used to calculate the MHHI_Deltas and with the nature of the MHHI_Delta itself. First, the data on institutional investors’ holdings are taken from Schedule 13 filings, which report aggregate holdings across all the institutional investor’s funds. Using these data masks the actual incentives of the institutional investors with respect to investments in any individual company or industry. Second, the construction of the MHHI_Delta suffers from serious endogeneity concerns, both in investors’ shareholdings and in market shares. Finally, the MHHI_Delta, while seemingly intuitive, is an empirical unknown. While HHI is theoretically bounded in a way that lends to interpretation of its calculated value, the same is not true for MHHI_Delta. This makes any inference or policy based on nominal values of MHHI_Delta completely arbitrary at best.

We’ll expand on each of these concerns in upcoming posts. We will then take on the problems with the policy proposals being offered in response to the common ownership ‘problem.’







Last week Thom posted about the government’s attempt to hide the cost of taxes and regulatory fees in commercial airfares. Apparently Spirit Airlines is highlighting another government-imposed cost of doing business by advertising a new $2/ticket fee that the airline has imposed. According a CNN report yesterday:

Spirit Airlines says a new federal regulation aimed at protecting consumers is forcing it to charge passengers an additional $2 for a ticket.

The fee, which Spirit calls the “Department of Transportation Unintended Consequences Fee,” has been added to each ticket effective immediately, according to Misty Pinson, a Spirit spokeswoman.

The new DOT regulation allows passengers to change flights within 24 hours of booking without paying a penalty. The airline says the regulation forces them to hold the seat for someone who may or may not want to fly. As a consequence, someone who really does want to fly wouldn’t be able to buy that seat because the airline is holding it for someone who might or might not end up taking it.

In short, DOT is requiring airlines to give consumers a real option to change their flight plans at zero cost within a 24 hour window. Spirit rightly recognizes that options have value. Not only is there a value to consumers in ‘buying’ such an option, there is a cost associated with providing the option; in this case, the opportunity cost of selling seats that may be held for someone that will exercise the option to cancel without a fee.

Obviously, DOT head Ray LaHood is unimpressed.

“This is just another example of the disrespect with which too many airlines treat their passengers,” Department of Transportation Secretary Ray LaHood said in an e-mailed statement. “Rather than coming up with new and unnecessary fees to charge their customers, airlines should focus on providing fair and transparent service — that’s what our common sense rules are designed to ensure.”

Perhaps Mr. LaHood doesn’t understand the concept of options and option value. The right, but not the obligation, to undertake an activity (particularly under pre-specified terms) is clearly an economic good.  The very notion that DOT’s new regulation is touted as “consumer friendly” recognizes that it creates additional value for consumers. That is, it’s giving something away that is of value…a property right to change one’s mind at zero cost. However, it is disingenuous of Mr. LaHood to object to the idea that giving away value imposes a cost on the one providing the value (and I don’t mean the DOT, but the airlines who must honor the consumer’s exercise of the option).

A better solution might be to require airlines to explicitly offer the option of a no-penalty change within a 24-hour window. Then consumers could choose whether to pay the fee and airlines might discover the true market value of that option. Spirits’ $2 may be too high. More likely, it’s too low. Many airlines already do offer the option of a no-fee cancellation and the fare differential is much higher than $2, but that option typically has a much longer maturity…any time after booking up until departure. A shorter maturity window should command a lower option value.

Spirit Airlines may be the epitome of nickle-and-diming air travel consumers, something many consumers (myself included in some cases) don’t appreciate. However, there is no denying that Spirit understands the nature of options and their value. And there’s also no denying that, based on its stock price over the past year, Spirit is doing at least as well as industry leaders in providing consumers value for the options they choose. Perhaps instead of casting aspersions, Mr LaHood and his staff should invite Spirit to teach them about this fairly fundamental concept of options and option value rather than imposing regulations with so little regard for their true costs.