I don’t know if I ever loved United Airlines, but an irrational loyalty—of the kind usually associated with sports franchises—kept me flying the friendly skies with them for much of my adult life. It started when I lived in Chicago, the main United hub, where I’d slowly grown an affection for the blue and gray colors, the Gershwin music, and the heated mixed nuts. Over the years, I’d flown nearly seven hundred thousand miles. I suppose you could say that I thought I had settled on an airline, maybe for life.

That’s about when, in 2011 or so, a weirdly optimistic man began to appear on my in-flight screen alongside the safety warnings. Continental and United were becoming “the world’s leading airline,” he said; changes were being made, and “I think you’ll like them.” There was the unmistakable tone of a parent breaking unwelcome news to his children.

Modern American corporations rarely degrade service in bold, attention-getting ways. Rather, it is a kind of suffering by a thousand cuts, each individually unnoticeable but collectively defeating. On the “new” United, seats got smaller as the airline jammed more people into the same tube; upgrades, to escape the sardine effect, seemed to become harder to book. The number of boarding groups began to resemble something like a caste system; “change fees,” which have always been outrageous, grew higher (two hundred dollars for domestic, three hundred dollars for international), while baggage fees soared to as high as a hundred dollars. The cross-country flights somehow seemed to all be on old, broken-down planes, while gate agents and flight attendants all just seemed crabbier. Yet, I remained, through the indignities, the outrages, and the general descent into lousiness.

I suppose that everyone has his breaking point. For me, it was while trying to pre-board an overcrowded flight to Miami with a noisy baby in my arms, only to be ordered back in line by a curt agent. At that moment, I realized that United had quietly eliminated the traditional practice of pre-boarding “passengers with small children,” choosing to favor a few élite fliers over the convenience of everyone else. United spokesman Charles Hobart would describe the new boarding policy as an improvement: “We figured it would be better to simplify that process and reduce the number of boarding groups.”

The United merger is a grand example of a consumer sinkhole—a merger that proves to be not just a onetime event but an ongoing disaster for consumers (and shareholders) who suffer for years after. I wasn’t the only one who noticed the airline’s descent. Since 2011, United has piled up a mountain of consumer complaints (according to one report, only Spirit has more per passenger) and has repeatedly tallied some of the worst quality rankings in the nation, trailing even discount airlines like Frontier and AirTran. A Web site named Untied.com collected these complaints; United tried to sue it out of existence.

The sinkhole effect—which is not confined to airlines—means that we need to take a much closer look at mega-mergers in the essential industries whose services are hard to avoid and which have a disproportionate effect on quality of life. Looking at examples from other industries, like hospitals, can be even more alarming. During the early aughts, the Federal Trade Commission analyzed several completed hospital mergers. Those studies revealed two unmistakable results: 1) an increase in prices explainable only by a reduction in competition, and 2) the same or worse outcomes, as measured by indicators that included patient mortality. Other studies have largely confirmed the results. Higher prices and more dead patients; it doesn’t really get worse than that.

The Justice Department and the Federal Trade Commission are supposed to stop mergers that are bad for consumers, but degradation of service, with its direct effects on consumer welfare, does not get enough attention. Back in 2010, United and Continental made the usual bland promises: “great products and service for our customers, career opportunities for our people and consistent returns for our shareholders.” That was a quote from the outgoing United C.E.O., Glenn Tilton, who received nearly seventeen million dollars after agreeing to allow his airline to be ruined. (He was also given free flights for life, but, unfortunately for him, that doesn’t carry over to Delta.) The two airlines convinced the Justice Department that there was too little overlap between them to cause any competitive harm. (In practice, according to the Wall Street Journal, the combined airline raised prices by as much as fifty-seven per cent on routes made newly uncompetitive.) After forcing the new United to give some of its takeoff and landing rights to Southwest, the Justice Department allowed the merger to go ahead, to consumers’ collective chagrin.

The decline in customer service that followed wasn’t hard to predict: in hearings, in 2010, witnesses made clear what was coming. William McGee, of the Consumers Union, warned that “a clash of corporate cultures is virtually guaranteed, particularly after layoffs. These sterile corporate terms—downsizing, right-sizing, outsourcing, offshoring, furloughing—really mean two workforces will experience more trauma and jockeying for position on blended seniority lists. Inevitably, this will lead to employee morale issues and slowdowns due to melding of policies, procedures, and technologies.” He was exactly right.

You might think that, given competition, there’s no reason to worry about the effects of a mess like United-Continental. Consumers can always switch to friendlier skies, right? But competition, while helpful, is an insufficient remedy for bad customer service. For one thing, on some routes, there is almost no alternative to United. More insidious is the fact that United’s low standards have spread. The airline’s increases in change fees, for example, were quickly copied by many of its competitors (Southwest being one exception). As airlines merge, competitors collude by taking turns raising fees or providing a lower level of service, making the bad treatment of consumers contagious. Yesterday’s outrage soon becomes today’s industry standard. Decent behavior is treated as a perk.

The United story should affect how we consider present and future mergers, like the proposed takeover of Time Warner by Comcast. Two companies, neither renowned for customer service, want to merge, with nary an indication of how this might be good for the public. Rather, there is good reason to think that the outcome will be another United Airlines, and that the nation’s largest cable company will offer higher prices and poorer service while trying to prevent new forms of television, like Internet TV, from getting better or cheaper.

The quality of our day-to-day life has come, in large part, to depend on a few companies that are responsible for the service-intensive industries upon which we all rely. I’ve come to think that the ritualized abuse that we, as consumers, have become accustomed to in so many areas of life is a sad indictment of our civilization. So, to paraphrase Ronald Reagan, I didn’t actually leave United Airlines: the airline left me.