NEW YORK — In 1960, black students staged sit-ins that forced Woolworth’s to desegregate its lunch counters, and other stores and restaurants followed suit.
In 1986, General Motors, Coca-Cola, and dozens of other US corporations pulled out of apartheid-era South Africa after years of pressure from activists, college students, and investors.
Last week, four major retailers placed restrictions on gun sales that are stronger than federal law.
Those are all rare examples of American companies getting out ahead of the politicians and the law on socially explosive issues. Such decisions are almost always made reluctantly, under huge pressure, and with an eye toward minimizing the effect on the bottom line.
The Feb. 14 massacre of 17 students and teachers at a Florida high school has set off a response from US businesses unlike any previous mass shooting.
Major corporations, including MetLife, Hertz, and Delta Air Lines, have cut ties to the National Rifle Association.
Walmart, Kroger, L.L. Bean, and Dick’s Sporting Goods announced they will no longer sell guns to anyone under 21. Dick’s also banned the sale of assault-style rifles, a step Walmart took in 2015. And Dick’s CEO went even further by calling for tougher gun laws.
BlackRock, an investment firm that manages more than $6 trillion in assets, said last week that it is asking gun makers and retailers how they are responding to the Florida massacre.
The New York firm, a major holder of gun manufacturer stock, said it is also looking into creating new investment funds that exclude firearm makers and retailers.
These actions amounted to an act of defiance against the NRA and its allies in Washington who have vehemently opposed any ban on AR-15s and other semiautomatic weapons or a higher age limit for gun purchases.
‘‘What we are seeing is a real shift,’’ said Mimi Chakravorti, executive director of strategy at the brand consulting firm Landor. ‘‘I think right now, companies are acting ahead of the government because they are seeing that the changes are too slow.’’
The actions of the businesses came in response to protests by the students who survived the shooting at Marjory Stoneman Douglas High School and to growing calls by consumers for boycotts against companies that do business with the NRA or gun manufacturers.
The company decisions are not much of a sacrifice from a business point of view. Most of Dick’s business, for instance, is in other types of sporting goods, such as sneakers and basketballs. Guns and ammunition are estimated to account for only 8 percent of sales.
Walmart has not said how much of its business comes from guns, but when the company stopped offering AR-15s in 2015, it cited declining sales.
Roger Beahm, a professor of marketing at Wake Forest University School of Business, said smaller retailers will probably capitalize on the situation by selling the weapons the major chains will no longer handle.
But the corporate reaction could affect the wider gun debate, in conjunction with political and legal challenges.
Adam Winkler, a law professor at UCLA who has written extensively about gun policy, said the NRA is unlikely to change, but politicians might.
‘‘I don’t think the NRA is going to bow down or buckle to pressure,’’ Winkler said. ‘‘However, the gun debate may change to the extent that this is being driven by companies’ sense of what consumers want. That might affect elected officials on Election Day.’’
It is rare for a company to drop products out of social concern. When it happens, the calculation is that any loss of revenue will be offset by increased customer loyalty in the long term, Beahm said.
He cited the example of CVS Health, which stopped selling cigarettes and other tobacco products in 2014, a decision that cost $2 billion in revenue but was well received by its customers.
In the case of guns, the calculation of whether to jump into the debate or sit on the sidelines is tricky because the country is so divided on the issue.
Delta Air Lines, for example, faced retribution for cutting ties to the NRA. Georgia’s Republican state lawmakers voted Thursday to kill a proposed tax break on jet fuel that would have saved the airline millions.
While polls show the country is split on gun controls, there is widespread support for some measures opposed by the NRA, such as universal background checks.
The debate over whether it is the duty of corporations to weigh in on social issues goes back decades. In 1962, economist Milton Friedman, in his book ‘‘Capitalism and Freedom,’’ argued that the only social responsibility of business was to increase profits and play by the rules.
But in recent years, US companies have found it increasingly difficult to avoid being drawn into America’s culture wars.
That was dramatically illustrated when Indiana and North Carolina faced a backlash from businesses that threatened to boycott the states over laws that were deemed discriminatory toward gay and transgender people. Bank of America, American Airlines, and IBM, were among dozens of companies that spoke out.
A big difference from decades past is the strengthening voice of consumers, who now have a plethora of choices for where to spend their money and social media platforms for making their views heard, Chakravorti said.
