THE tragic shooting in Las Vegas on October 1st took many more lives than were lost in recent terror attacks in Europe including in London and Manchester. But while Donald Trump responded to those attacks with numerous tweets, he was comparitively quiet over the Las Vegas slaughter. In this case at least, the president’s relative level of social media concern appears to reflect broader American attitudes. Past evidence suggests that mass shootings at home do not have the same impact on American behaviour that terrorism abroad does. While that is good news for the nearly one in three of all workers in the Southern Nevada region who are employed by the leisure and hospitality industry, it also points to one reason why America’s gun laws are so hard to reform.

Until Las Vegas, the most deadly mass shooting in recent American history was the attack in June 2016 at Pulse nightclub in Orlando, Florida—another city that is economically dependent on tourism. But that attack had no noticeable impact on tourist arrivals to the region, which climbed from 66m to 68m between 2015 and 2016.

If tourists similarly continue to arrive in Las Vegas despite the shooting tragedy, the reaction would be reasonable. Mass shootings are too random and still too rare to justify changing travel plans. Most people who are killed by guns in America are not killed by mass shooting events, and despite the epidemic of gun violence as a whole, other unpredictable threats to life loom larger still. Since the Sandy Hook Elementary School mass shooting in December 2012, 1,715 people have been killed in shootings in which four or more people were injured or died according to the Gun Violence Archive. That compares to over 15,000 total gun deaths in 2016 alone, or the 32,000 each year who die in vehicle accidents.

The risk of an American tourist dying in a terror attack while abroad is considerably lower than the risk the average American faces being shot while staying at home. The State Department reports on American citizens who die abroad from ‘non-natural’ causes. Between 2003 and 2016, exclusive of the war zones of Afghanistan and Iraq, 99 citizens have died in terror incidents overseas. That compares to 3,381 American citizens overseas who have died in vehicle accidents over that same time. It is about 0.9% of total American overseas deaths from non-natural causes over that time. And it compares to 74m outbound travel departures from the United States in 2015 alone.

Despite the lower risk, the reaction of tourists in the face of terror attacks contrasts markedly with their reasoned resolve in response to domestic mass-shootings. From 2000 to 2003, cities including Mombasa, New York, Madrid, London, Bali and Cairo all experienced significant declines in the numbers of arrivals after terrorist incidents, for example. Maria Santana-Gallego, an economist, and her colleagues estimated that a 1% increase in the ratio of terrorist attacks per 10,000 inhabitants in a country reduces tourist arrivals by 2.3%. This is a much larger effect on arrivals than the violent crime rate: a 1% increase in homicides per 10,000 inhabitants reduces inbound tourism by 0.02%.

That travellers including Americans react to the threat of mass violence overseas but ignore larger risks at home points to the reality that domestic gun violence lacks comparative salience as a reason to act. It helps to explain why Americans are far more willing to support efforts to reduce the terror threat like travel restrictions, invasive search procedures and surveillance than they are to back meaningful domestic gun control. And the fact that mass shootings have little impact on behaviour—or tourism receipts—means that the only economic effect of mass shootings in America may be a small increase in the share prices of gun manufacturers, in anticipation of greater sales.