What is a search engine? This might seem like an innocuous question, but it lies at the heart of the US Department of Justice and state Attorneys’ General antitrust complaint against Google, as well as the European Commission’s Google Search and Android decisions. It is also central to a report published by the UK’s Competition & Markets Authority (“CMA”). To varying degrees, all of these proceedings are premised on the assumption that Google enjoys a monopoly/dominant position over online search. But things are not quite this simple.
Despite years of competition decisions and policy discussions, there are still many unanswered questions concerning the operation of search markets. For example, it is still unclear exactly which services compete against Google Search, and how this might evolve in the near future. Likewise, there has only been limited scholarly discussion as to how a search engine monopoly would exert its market power. In other words, what does a restriction of output look like on a search platform — particularly on the user side?
Answering these questions will be essential if authorities wish to successfully bring an antitrust suit against Google for conduct involving search. Indeed, as things stand, these uncertainties greatly complicate efforts (i) to rigorously define the relevant market(s) in which Google Search operates, (ii) to identify potential anticompetitive effects, and (iii) to apply the quantitative tools that usually underpin antitrust proceedings.
In short, as explained below, antitrust authorities and other plaintiffs have their work cut out if they are to prevail in court.
Consumers demand information
For a start, identifying the competitive constraints faced by Google presents authorities and plaintiffs with an important challenge.
Even proponents of antitrust intervention recognize that the market for search is complex. For instance, the DOJ and state AGs argue that Google dominates a narrow market for “general search services” — as opposed to specialized search services, content sites, social networks, and online marketplaces, etc. The EU Commission reached the same conclusion in its Google Search decision. Finally, commenting on the CMA’s online advertising report, Fiona Scott Morton and David Dinielli argue that:
General search is a relevant market […]
In this way, an individual specialized search engine competes with a small fraction of what the Google search engine does, because a user could employ either for one specific type of search. The CMA concludes that, from the consumer standpoint, a specialized search engine exerts only a limited competitive constraint on Google.
(Note that the CMA stressed that it did not perform a market definition exercise: “We have not carried out a formal market definition assessment, but have instead looked at competitive constraints across the sector…”).
In other words, the above critics recognize that search engines are merely tools that can serve multiple functions, and that competitive constraints may be different for some of these. But this has wider ramifications that policymakers have so far overlooked.
When quizzed about his involvement with Neuralink (a company working on implantable brain–machine interfaces), Elon Musk famously argued that human beings already share a near-symbiotic relationship with machines (a point already made by others):
The purpose of Neuralink [is] to create a high-bandwidth interface to the brain such that we can be symbiotic with AI. […] Because we have a bandwidth problem. You just can’t communicate through your fingers. It’s just too slow.
Commentators were quick to spot this implications of this technology for the search industry:
Imagine a world when humans would no longer require a device to search for answers on the internet, you just have to think of something and you get the answer straight in your head from the internet.
As things stand, this example still belongs to the realm of sci-fi. But it neatly illustrates a critical feature of the search industry.
Search engines are just the latest iteration (but certainly not the last) of technology that enables human beings to access specific pieces of information more rapidly. Before the advent of online search, consumers used phone directories, paper maps, encyclopedias, and other tools to find the information they were looking for. They would read newspapers and watch television to know the weather forecast. They went to public libraries to undertake research projects (some still do), etc.
And, in some respects, the search engine is already obsolete for many of these uses. For instance, virtual assistants like Alexa, Siri, Cortana and Google’s own Google Assistant offering can perform many functions that were previously the preserve of search engines: checking the weather, finding addresses and asking for directions, looking up recipes, answering general knowledge questions, finding goods online, etc. Granted, these virtual assistants partly rely on existing search engines to complete tasks. However, Google is much less dominant in this space, and search engines are not the sole source on which virtual assistants rely to generate results. Amazon’s Alexa provides a fitting example (here and here).
Along similar lines, it has been widely reported that 60% of online shoppers start their search on Amazon, while only 26% opt for Google Search. In other words, Amazon’s ability to rapidly show users the product they are looking for somewhat alleviates the need for a general search engine. In turn, this certainly constrains Google’s behavior to some extent. And much of the same applies to other websites that provide a specific type of content (think of Twitter, LinkedIn, Tripadvisor, Booking.com, etc.)
Finally, it is also revealing that the most common searches on Google are, in all likelihood, made to reach other websites — a function for which competition is literally endless:
The upshot is that Google Search and other search engines perform a bundle of functions. Most of these can be done via alternative means, and this will increasingly be the case as technology continues to advance.
This is all the more important given that the vast majority of search engine revenue derives from roughly 30 percent of search terms (notably those that are linked to product searches). The remaining search terms are effectively a loss leader. And these profitable searches also happen to be those where competition from alternative means is, in all likelihood, the strongest (this includes competition from online retail platforms, and online travel agents like Booking.com or Kayak, but also from referral sites, direct marketing, and offline sources). In turn, this undermines US plaintiffs’ claims that Google faces little competition from rivals like Amazon, because they don’t compete for the entirety of Google’s search results (in other words, Google might face strong competition for the most valuable ads):
108. […] This market share understates Google’s market power in search advertising because many search-advertising competitors offer only specialized search ads and thus compete with Google only in a limited portion of the market.
Critics might mistakenly take the above for an argument that Google has no market power because competition is “just a click away”. But the point is more subtle, and has important implications as far as market definition is concerned.
Authorities should not define the search market by arguing that no other rival is quite like Google (or one if its rivals) — as the DOJ and state AGs did in their complaint:
90. Other search tools, platforms, and sources of information are not reasonable substitutes for general search services. Offline and online resources, such as books, publisher websites, social media platforms, and specialized search providers such as Amazon, Expedia, or Yelp, do not offer consumers the same breadth of information or convenience. These resources are not “one-stop shops” and cannot respond to all types of consumer queries, particularly navigational queries. Few consumers would find alternative sources a suitable substitute for general search services. Thus, there are no reasonable substitutes for general search services, and a general search service monopolist would be able to maintain quality below the level that would prevail in a competitive market.
And as the EU Commission did in the Google Search decision:
(162) For the reasons set out below, there is, however, limited demand side substitutability between general search services and other online services. […]
(163) There is limited substitutability between general search services and content sites. […]
(166) There is also limited substitutability between general search services and specialised search services. […]
(178) There is also limited substitutability between general search services and social networking sites.
Ad absurdum, if consumers suddenly decided to access information via other means, Google could be the only firm to provide general search results and yet have absolutely no market power.
Take the example of Yahoo: Despite arguably remaining the most successful “web directory”, it likely lost any market power that it had when Google launched a superior — and significantly more successful — type of search engine. Google Search may not have provided a complete, literal directory of the web (as did Yahoo), but it offered users faster access to the information they wanted. In short, the Yahoo example shows that being unique is not equivalent to having market power. Accordingly, any market definition exercise that merely focuses on the idiosyncrasies of firms is likely to overstate their actual market power.
Given what precedes, the question that authorities should ask is thus whether Google Search (or another search engine) performs so many unique functions that it may be in a position to restrict output. So far, no one appears to have convincingly answered this question.
What does market power look like in search?
Similar uncertainties surround the question of how a search engine might restrict output, especially on the user side of the search market. Accordingly, authorities will struggle to produce evidence (i) the Google has market power, especially on the user side of the market, and (ii) that its behavior has anticompetitive effects.
Consider the following:
The SSNIP test (which is the standard method of defining markets in antitrust proceedings) is inapplicable to the consumer side of search platforms. Indeed, it is simply impossible to apply a hypothetical 10% price increase to goods that are given away for free.
This raises a deeper question: how would a search engine exercise its market power?
For a start, it seems unlikely that it would start charging fees to its users. For instance, empirical research pertaining to the magazine industry (also an ad-based two-sided market) suggests that increased concentration does not lead to higher magazine prices. Minjae Song notably finds that:
Taking the advantage of having structural models for both sides, I calculate equilibrium outcomes for hypothetical ownership structures. Results show that when the market becomes more concentrated, copy prices do not necessarily increase as magazines try to attract more readers.
It is also far from certain that a dominant search engine would necessarily increase the amount of adverts it displays. To the contrary, market power on the advertising side of the platform might lead search engines to decrease the number of advertising slots that are available (i.e. reducing advertising output), thus showing less adverts to users.
Finally, it is not obvious that market power would lead search engines to significantly degrade their product (as this could ultimately hurt ad revenue). For example, empirical research by Avi Goldfarb and Catherine Tucker suggests that there is some limit to the type of adverts that search engines could profitably impose upon consumers. They notably find that ads that are both obtrusive and targeted decrease subsequent purchases:
Ads that match both website content and are obtrusive do worse at increasing purchase intent than ads that do only one or the other. This failure appears to be related to privacy concerns: the negative effect of combining targeting with obtrusiveness is strongest for people who refuse to give their income and for categories where privacy matters most.
The preceding paragraphs find some support in the theoretical literature on two-sided markets literature, which suggests that competition on the user side of search engines is likely to be particularly intense and beneficial to consumers (because they are more likely to single-home than advertisers, and because each additional user creates a positive externality on the advertising side of the market). For instance, Jean Charles Rochet and Jean Tirole find that:
The single-homing side receives a large share of the joint surplus, while the multi-homing one receives a small share.
This is just a restatement of Mark Armstrong’s “competitive bottlenecks” theory:
Here, if it wishes to interact with an agent on the single-homing side, the multi-homing side has no choice but to deal with that agent’s chosen platform. Thus, platforms have monopoly power over providing access to their single-homing customers for the multi-homing side. This monopoly power naturally leads to high prices being charged to the multi-homing side, and there will be too few agents on this side being served from a social point of view (Proposition 4). By contrast, platforms do have to compete for the single-homing agents, and high profits generated from the multi-homing side are to a large extent passed on to the single-homing side in the form of low prices (or even zero prices).
All of this is not to suggest that Google Search has no market power, or that monopoly is necessarily less problematic in the search engine industry than in other markets.
Instead, the argument is that analyzing competition on the user side of search platforms is unlikely to yield dispositive evidence of market power or anticompetitive effects. This is because market power is hard to measure on this side of the market, and because even a monopoly platform might not significantly restrict user output.
That might explain why the DOJ and state AGs analysis of anticompetitive effects is so limited. Take the following paragraph (provided without further supporting evidence):
167. By restricting competition in general search services, Google’s conduct has harmed consumers by reducing the quality of general search services (including dimensions such as privacy, data protection, and use of consumer data), lessening choice in general search services, and impeding innovation.
Given these inherent difficulties, antitrust investigators would do better to focus on the side of those platforms where mainstream IO tools are much easier to apply and where a dominant search engine would likely restrict output: the advertising market. Not only is it the market where search engines are most likely to exert their market power (thus creating a deadweight loss), but — because it involves monetary transactions — this side of the market lends itself to the application of traditional antitrust tools.
Looking at the right side of the market
Finally, and unfortunately for Google’s critics, available evidence suggests that its position on the (online) advertising market might not meet the requirements necessary to bring a monopolization case (at least in the US).
For a start, online advertising appears to exhibit the prima facie signs of a competitive market. As Geoffrey Manne, Sam Bowman and Eric Fruits have argued:
Over the past decade, the price of advertising has fallen steadily while output has risen. Spending on digital advertising in the US grew from $26 billion in 2010 to nearly $130 billion in 2019, an average increase of 20% a year. Over the same period the Producer Price Index for Internet advertising sales declined by nearly 40%. The rising spending in the face of falling prices indicates the number of ads bought and sold increased by approximately 27% a year. Since 2000, advertising spending has been falling as a share of GDP, with online advertising growing as a share of that. The combination of increasing quantity, decreasing cost, and increasing total revenues are consistent with a growing and increasingly competitive market.
Second, empirical research suggests that the market might need to be widened to include offline advertising. For instance, Avi Goldfarb and Catherine Tucker show that there can be important substitution effects between online and offline advertising channels:
Using data on the advertising prices paid by lawyers for 139 Google search terms in 195 locations, we exploit a natural experiment in “ambulance-chaser” regulations across states. When lawyers cannot contact clients by mail, advertising prices per click for search engine advertisements are 5%–7% higher. Therefore, online advertising substitutes for offline advertising.
Of course, a careful examination of the advertising industry could also lead authorities to define a narrower relevant market. For example, the DOJ and state AG complaint argued that Google dominated the “search advertising” market:
97. Search advertising in the United States is a relevant antitrust market. The search advertising market consists of all types of ads generated in response to online search queries, including general search text ads (offered by general search engines such as Google and Bing) […] and other, specialized search ads (offered by general search engines and specialized search providers such as Amazon, Expedia, or Yelp).
Likewise, the European Commission concluded that Google dominated the market for “online search advertising” in the AdSense case (though the full decision has not yet been made public). Finally, the CMA’s online platforms report found that display and search advertising belonged to separate markets.
But these are empirical questions that could dispositively be answered by applying traditional antitrust tools, such as the SSNIP test. And yet, there is no indication that the authorities behind the US complaint undertook this type of empirical analysis (and until its AdSense decision is made public, it is not clear that the EU Commission did so either). Accordingly, there is no guarantee that US courts will go along with the DOJ and state AGs’ findings.
In short, it is far from certain that Google currently enjoys an advertising monopoly, especially if the market is defined more broadly than that for “search advertising” (or the even narrower market for “General Search Text Advertising”).
Concluding remarks
The preceding paragraphs have argued that a successful antitrust case against Google is anything but a foregone conclusion. In order to successfully bring a suit, authorities would notably need to figure out just what market it is that Google is monopolizing. In turn, that would require a finer understanding of what competition, and monopoly, look like in the search and advertising industries.