The increase in both international and domestic competition, enabled and driven by deregulation and globalization, the repeat of decennial crises that encourage industry restructuring, and the rise of profit rates after the economic recovery began in 1982 that enabled reorganization have together brought about one of the most extraordinary waves of business consolidation via mergers and acquisitions (M&As) in the history of US capitalism. M&A movements tend to come in waves. They are part of the ongoing reorganization of capital under the pressures of competition, their rhythms determined partly by falling and then rising rates of profit. In the United States there have been six major waves of mergers and acquisitions in which business has been reshaped: 1897–1904, 1916–29, 1965–69, 1984–89, 1992–2000, and 2003 to the present. Each of these merger movements attempted to resolve problems associated with falling rates of profits leading to recessions and to take advantage of the resumption of profitability to increase efficiency and market share through mergers.

In conventional terms merger waves are the product of economic expansion, on the one hand, and capital liquidity, on the other. From a Marxist perspective more particularly, they rise and fall with the rate of profit. Using the rate of profit-of-enterprise calculated by Anwar Shaikh and the empirical information on merger numbers and value provided by Gaughan and Pautler, the four post–World War II merger waves (1965–69, 1980–90, 1992–2000, and 2003–present) correspond to a remarkable degree with the rise and fall of profit-of-enterprise rates over this long period.