The U.S. Department of Justice (DOJ) and the Federal Trade Commission (FTC) share responsibility for evaluating mergers. Firms with more than $50 million in assets are required under the Hart-Scott-Rodino Act to file with the government an intention to merge with another firm. The government then has a limited amount of time to either approve the merger or request more information (called a second request). Once the firms have complied with the second request, the government again has a limited amount of time before it either approves the merger or sues to block it. The government agencies themselves don’t stop the merger, but instead they sue to block the merger, asking a federal judge to prevent the merger as a violation of one of the antitrust laws. Mergers are distinct from other violations because they have not yet occurred at the time the lawsuit is brought, so there is no threat of damages or criminal penalties; the only potential penalty imposed on the merging parties is that the proposed merger may be blocked.
Many proposed mergers result in settlements. As part of the settlement associated with GE’s purchase of Radio Corporation of America (RCA) in 1986, a small appliance division of GE’s was sold to Black & Decker, thereby maintaining competition in the small kitchen appliance market. In the 1999 merger of oil companies Exxon and Mobil, a California refinery, shares in oil pipelines connecting the Gulf with the Northeast, and thousands of gas stations were sold to other companies. The 1996 merger of Kimberley-Clark and Scott Paper would have resulted in a single company with over 50% of the facial tissue and baby wipes markets, and in both cases divestitures of production capacity and the Scotties brand name preserved competition in the markets. Large bank mergers, oil company mergers, and other large companies usually present some competitive concerns, and the majority of these cases are solved by divestiture of business units to preserve competition.
A horizontal mergerA merger of competitors. is a merger of competitors, such as Exxon and Mobil or two banks located in the same city. In contrast, a vertical mergerA merger between an input supplier and an input buyer. is a merger between an input supplier and input buyer. The attempt by book retailer Barnes and Noble to purchase the intermediary Ingram, a company that buys books from publishers and sells to retailers but doesn’t directly sell to the public, would have resulted in a vertical merger. Similarly, Disney is a company that sells programs to television stations (among other activities), so its purchase of TV network ABC was a vertical merger. The AOL-Time Warner merger involved several vertical relationships. For example, Time Warner is a large cable company, and cable represents a way for AOL to offer broadband services. In addition, Time Warner is a content provider, and AOL delivers content to Internet subscribers.
Vertical mergers raise two related problems: foreclosure and raising rivals’ costs. ForeclosureDenying access to necessary inputs. refers to denying access to necessary inputs. Thus, the AOL-Time Warner merger threatened rivals to AOL Internet service (like EarthLink) with an inability to offer broadband services to consumers with Time Warner cable. This potentially injures competition in the Internet service market, forcing Time Warner customers to use AOL. In addition, by bundling Time Warner content and AOL Internet service, users could be forced to purchase AOL Internet service in order to have access to Time Warner content. Both of these threaten foreclosure of rivals, and both were resolved to the government’s satisfaction by promises that the merged firm would offer equal access to rivals.
Raising rivals’ costsIncreasing input prices as a means of harming a rival. is a softer version of foreclosure. Rather than deny access to content, AOL Time Warner could instead make the content available under disadvantageous terms. For example, American Airlines developed the Sabre computerized reservation system, which was used by about 40% of travel agents. This system charged airlines, rather than travel agents, for bookings. Consequently, American Airlines had a mechanism for increasing the costs of its rivals: by increasing the price of bookings on the Sabre system. The advantage to American Airlines was not just increased revenue of the Sabre system but also the hobbling of airline rivals. Similarly, banks offer free use of their own automated teller machines (ATMs), but they charge the customers of other banks. Such charges raise the costs of customers of other banks, thus making other banks less attractive and providing an advantage in the competition for bank customers.
The DOJ and the FTC periodically issue horizontal merger guidelines, which set out how mergers will be evaluated. This is a three-step procedure for each product that the merging companies have in common.
The procedure starts by identifying product markets. To identify a product market, start with a product or products produced by both companies. Then ask if the merged parties can profitably raise price by a small but significant and nontransitory increase in price, also known as a SSNIPA small but significant and nontransitory increase in price. (pronounced “snip”). A SSNIP is often taken to be a 5% price increase, which must prevail for several years. If the companies can profitably increase price by a SSNIP, then they are judged to have monopoly power and consumers will be directly harmed by the merger. (This is known as a unilateral effectIn antitrust, a situation in which merging parties increase price unilaterally after the merger is consummated. because the merging parties will increase price unilaterally after the merger is consummated.) If they can’t increase prices, then an additional product has to be added to the group; generally the best substitute is added. Ask whether a hypothetical monopoly seller of these three products can profitably raise price. If it can, an antitrust market has been identified; if it cannot, yet another substitute product must be added. The process stops adding products when enough substitutes have been identified that, if controlled by a hypothetical monopoly, would have their prices significantly increased.
The logic of product market definition is that, if a monopoly wouldn’t increase price in a meaningful way, then there is no threat to consumers—any price increase won’t be large or won’t last. The market is defined by the smallest set of products for which consumers can be harmed. The test is also known as the hypothetical monopoly test.
The second step is to identify a geographic market. The process starts with an area in which both companies sell and asks if the merged company has an incentive to increase price by a SSNIP. If it does, that geographic area is a geographic market. If it does not, it is because buyers are substituting outside the area to buy cheaply, and the area must be expanded. For example, owning all the gas stations on a corner doesn’t let one increase price profitably because an increase in price leads to substitution to gas stations a few blocks away. If one company owned all the stations in a half-mile radius, would it be profitable to increase price? Probably not because there would still be significant substitution to more distant stations. Suppose, instead, that one owned all the stations for a 15-mile radius. Then an increase in price in the center of the area is not going to be thwarted by too much substitution outside the area, and the likely outcome is that prices would be increased by such a hypothetical monopoly. In this case, a geographic market has been identified. Again, parallel to the product market definition, a geographic market is the smallest area in which competitive concerns would be raised by a hypothetical monopoly. In any smaller area, attempts to increase price are defeated by substitution to sellers outside the area.
The product and geographic markets together are known as a relevant antitrust marketA set of products sold in a geographic area in which a hypothetical monopoly can profitably raise price. (relevant for the purposes of analyzing the merger).
The third and last step of the procedure is to identify the level of concentration in each relevant antitrust market. The Hirschman-Herfindahl Index (HHI) is used for this purpose. The HHI is the sum of the squared market shares of the firms in the relevant antitrust market, and it is justified because it measures the price-cost margin in the Cournot model. Generally, in practice, the shares in percentage are used, which makes the scale range from 0 to 10,000. For example, if one firm has 40%, one has 30%, one has 20%, and the remaining firm has 10%, the HHI is 402 + 302 + 202 + 102 = 3,000.
Usually, anything over 1,800 is considered very concentrated, and anything over 1,000 is concentrated.
Suppose firms with shares x and y merge, and nothing in the industry changes besides the combining of those shares. Then the HHI goes up by (x + y)2 – x2 – y2 = 2xy. This is referred to as the change in the HHI. The merger guidelines suggest that the government will likely challenge mergers with (a) a change of 100 and a concentrated post-merger HHI, or (b) a change of 50 and a very concentrated post-merger HHI. It is more accurate in understanding the merger guidelines to say that the government likely won’t challenge unless either (a) or (b) is met. Even if the post-merger HHI suggests a very concentrated industry, the government is unlikely to challenge if the change in the HHI is less than 50.
Several additional factors affect the government’s decision. First, if the firms are already engaging in price discrimination, the government may define quite small geographic markets, possibly as small as a single customer. Second, if one firm is very small (less than 1%) and the other not too large (less than 35%), the merger may escape scrutiny because the effect on competition is likely small. Third, if one firm is going out of business, the merger may be allowed as a means of keeping the assets in the industry. Such was the case with Greyhound’s takeover of Trailways, a merger that produced a monopoly of the only intercity bus companies in the United States.
Antitrust originated in the United States, and the United States remains the most vigorous enforcer of antitrust laws. However, the European Union has recently taken a more aggressive antitrust stance, and in fact it has blocked mergers that obtained tentative U.S. approval, such as GE and Honeywell.
Antitrust is, in some sense, the applied arm of oligopoly theory. Because real situations are so complex, the application of oligopoly theory to antitrust analysis is often challenging, and we have only scratched the surface of many of the more subtle issues of law and economics in this text. For example, intellectual property, patents, and standards all have their own distinct antitrust issues.
