A hundred years ago, the popular image of the worker was a sweaty toiler, his face smudged with coal dust or scorched by the blast furnace, oppressed by the industrial machine but not its total victim. He was coiled with potential energy that was frightening to some and inspiring to others—he had the country’s future in his muscular hands. By the time Studs Terkel published his oral history “Working,” forty years ago next month, that image had blurred. The Chicago steelworker at the start of the book was a working stiff, bored and trapped by his job but still able to take its existence for granted. And he now had company—among others, a hospital aide, a supermarket cashier, a pair of hair stylists. These were the last days of secure blue-collar work, and the beginning of wage stagnation in the service economy.

In the decades after 1974, the archetypal worker became a store greeter at Walmart—part time, nonunion, making near-poverty wages. The animating spirit of her working life was no longer the dignity of labor, the drama of factory strife, or the slackness of union bureaucracy—it was required cheerfulness barely concealing an unhappiness that she was too afraid to show. She was isolated, anxious, and, basically, powerless, under the constant threat of having no job at all.

As the bottom fell out of the working class, this attitude spread to other kinds of work, including the once formidable assembly line: employees at the Volkswagen plant in Chattanooga, who recently voted against joining the United Auto Workers, cited the fate of their counterparts in Detroit. Solidarity had become too risky—they were lucky just to be making nineteen dollars an hour.

When I wrote about Amazon—which is as emblematic of the American corporation in 2014 as U.S. Steel was in 1914 and Walmart in 1994—for a story in The New Yorker, earlier this month, I began to wonder what a company worker looked like. I found it hard to come up with an image. Amazon’s workforce is made up mainly of computer engineers and warehouse workers, but when you think of Amazon you don’t picture either one (and there aren’t many photographs to help your imagination). What you see, instead, is a Web site with a button that says “ADD TO CART” and a cardboard box with a smile printed on the side. Between clicking “BUY” and answering the door when U.P.S. arrives lies a mystery—a chain of events that only comes to mind if you make a conscious effort. The work is done by people you don’t see and don’t have to think about, which is partly what makes Amazon’s unmatched efficiency seem nearly miraculous.

The invisibility of work and workers in the digital age is as consequential as the rise of the assembly line and, later, the service economy. Whether as victim, demon, or hero, the industrial worker of the past century filled the public imagination in books, movies, news stories, and even popular songs, putting a grimy human face on capitalism while dramatizing the social changes and conflicts it brought. The guy stocking shelves and the girl scanning purchases at Target never occupied much of a place in the public mind, and certainly never a romantic one (no one composed a “Ballad of the Floor Associate”), but at least you had to look at them whenever you ventured out to stimulate the economy. They reminded you that low-priced Chinese-made goods were a mixed blessing—that many of the jobs being created in post-industrial America were crappy ones.

With work increasingly invisible, it’s much harder to grasp the human effects, the social contours, of the Internet economy. For example, a century ago there was a great debate over the trusts—enormous concentrations of economic power in oil, railroads, banking, steel. The trusts produced a historic backlash called Progressivism. Reformers were divided into two camps: the New Nationalists, led by Theodore Roosevelt and guided by the New Republic editor Herbert Croly, believed that monopoly was an inevitable and highly efficient feature of the industrial economy. The New Nationalists wanted not to break up monopolies but to regulate them in the public interest, necessitating a central government that was the equal of the big corporations. “Every man holds his property subject to the general right of the community to regulate its use to whatever degree the public welfare may require it,” Roosevelt said in Osawatomie, Kansas, in 1910, in a speech that inspired President Obama to talk about inequality a century later in the same place.

In the election of 1912, Roosevelt’s New Nationalism was opposed by the New Freedom of Woodrow Wilson, under the intellectual guidance of Louis Brandeis, the goal of which was to liberate individual enterprise and to eliminate monopoly power and its corrupting influence. Wilson embraced “that vision which sees that no society is renewed from the top but that every society is renewed from the bottom.” In practice, the difference between these two schools of thought was not as wide as the rhetoric of their proponents. “Whether the objective was to regulate monopoly or competition,” Arthur Schlesinger, Jr., later wrote, “the method was to meet the power of business by expanding the power of government.” Elements of both the New Nationalism and the New Freedom informed Progressive thought and its crowning achievement, the New Deal.

Today, we have our own concentrations of economic power. Instead of Standard Oil, U.S. Steel, the Union Pacific Railroad, and J. P. Morgan and Company, we have Amazon, Google, Apple, Facebook, and Microsoft. (Earlier this month, Google briefly passed Exxon Mobil as the second most valuable American company, after Apple, with a market capitalization of nearly four hundred billion dollars.) Among tech companies, dependent on rapid growth with huge network effects for revenue, competition for market share has become so routinely intense that Facebook’s purchase, last week, of the mobile-messaging company WhatsApp for nineteen billion dollars was reported as yet another tale of sudden, outlandish wealth creation, not as a dangerous consolidation of the messaging business in one company’s hands, which is taken as a given and probably a beneficial thing. Comcast’s proposed forty-five-billion-dollar takeover of Time Warner Cable raised a few eyebrows, but most observers expect it to go through. In banking, the Dodd-Frank reform law has provisions to minimize the kind of risky behavior that led to the financial crisis, but, in the name of global competitiveness, the too-big-to-fail banks just keep getting bigger.

The whole trend of antitrust policy for the past thirty years, continuing with the Obama Administration, has been to disregard monopoly in the interest of low consumer prices and greater “efficiency.” As Paul Krugman wrote, in the Times, of the Comcast deal, “There used to be a bipartisan consensus in favor of tough antitrust enforcement. During the Reagan years, however, antitrust policy went into eclipse, and ever since measures of monopoly power, like the extent to which sales in any given industry are concentrated in the hands of a few big companies, have been rising fast.”

Where is the great debate over bigness in our time? What public limits should be placed on the power of private companies to disrupt older industries, which usually involves destroying more jobs than can be created? What are the ideas for regulating monopoly or competition on the Internet? Who are the leaders and thinkers of the New New Nationalism and the New New Freedom? There are thoughtful, though fairly marginal, critics, such as Jaron Lanier, whose recent book “Who Owns the Future?” argues for giving users a share of the wealth in an Internet economy that requires their participation. Lanier stands in the philosophical tradition of Louis Brandeis, who regarded bigness as a result of financial manipulation more than the drive for efficiency. But the sheer size of the tech giants, and the economic and political power that comes with this, generates much less skepticism than Rockefeller and Morgan ever inspired.