Ethical consumerism is a type of consumer activism practiced through 'positive buying' in that ethical products are favoured, or 'moral boycott', that is negative purchasing and company-based purchasing.

The term "ethical consumer", now used generically, was first popularised by the UK magazine the Ethical Consumer, first published in 1989. Ethical Consumer magazine's key innovation was to produce 'ratings tables,' inspired by the criteria-based approach of the then emerging ethical investment movement. Ethical Consumer's ratings tables awarded companies negative marks (and from 2005 overall scores) across a range of ethical and environmental categories such a 'animal rights', 'human rights' and 'pollution and toxics', empowering consumers to make ethically informed consumption choices and providing campaigners with reliable information on corporate behaviour. Such criteria-based ethical and environmental ratings have subsequently become a commonplace both in providing consumer information and in business-to-business corporate social responsibility and sustainability ratings such as those provided by Innovest, Calvert, Domini, IRRC, TIAA-CREF and KLD Analytics. Today, Bloomberg and Reuters even provide "environmental, social and governance" ratings direct to the financial data screens of hundreds of thousands of stock market traders. The not-for-profit Ethical Consumer Research Association continues to publish Ethical Consumer magazine and its associated website, which provides free access to ethical ratings tables.

Milton Friedman (July 31, 1912 – November 16, 2006) was an American economist, statistician, and author who taught at the University of Chicago for more than three decades. He was a recipient of the Nobel Memorial Prize in Economic Sciences, and is known for his research on consumption analysis, monetary history and theory, and the complexity of stabilization policy. As a leader of the Chicago school of economics, he influenced the research agenda of the economics profession. A survey of economists ranked Friedman as the second most popular economist of the twentieth century behind John Maynard Keynes, and The Economist described him as "the most influential economist of the second half of the 20th century…possibly of all of it."

Friedman's challenges to what he later called "naive Keynesian" (as opposed to New Keynesian) theory began with his 1950s reinterpretation of the consumption function, and he became the main advocate opposing activist Keynesian government policies. In the late 1960s he described his own approach (along with all of mainstream economics) as using "Keynesian language and apparatus" yet rejecting its "initial" conclusions. During the 1960s he promoted an alternative macroeconomic policy known as "monetarism". He theorized there existed a "natural" rate of unemployment, and argued that governments could increase employment above this rate (e.g., by increasing aggregate demand) only at the risk of causing inflation to accelerate. He argued that the Phillips curve was not stable and predicted what would come to be known as stagflation. Friedman argued that, given the existence of the Federal Reserve, a constant small expansion of the money supply was the only wise policy.