Context matters in part because every human decision depends heavily on evaluative judgments, which in turn depend heavily on the contexts surrounding those judgments. Context shapes our judgments about mundane physical quantities, such as distance. 1/
Suppose, for instance, that you’re driving with your six-year-old to visit her grandparents and she asks, “Are we almost there yet?” You’ll say no if 10 miles remain on 12-mile journey, but you’ll say yes if those same 10 miles remain on a journey of 120 miles. 2/
Context also shapes judgments about temperature. If someone asks whether it is cold out, your answer will be different if it’s 60° on a sunny March afternoon in Montreal than if it’s a 60° November evening in Miami. 3/
Although the link between context and evaluation is uncontroversial among behavioral scientists, its importance goes almost completely unacknowledged in many public policy discussions. 4/
In large part, that’s because traditional economic models, which supply the theoretical underpinning of most policy discussions, completely ignore how context shapes human judgments. 5/
Context is heavily implicated, for example, in questionable decisions about safety. When my son Chris was 14, the left front quadrant of the helmet he’d been wearing was shattered in a serious bike accident. 6/ 
The emergency room physician who treated him told me that if Chris had not been wearing the helmet, we would be discussing funeral arrangements instead of the precautions necessary to prevent further injury to his broken collarbone. 7/
Despite considerable effort, I had never been able to get Chris’s older brothers to wear bike helmets. None of the other kids wear them, they correctly insisted, and unless I was physically present, they would often ride without one. 8/
I’m therefore extremely grateful to the New York State legislators who, several years after my older sons had left home, enacted a law requiring helmets for bicyclists under the age of 18. That law probably saved Chris’s life. 9/
Even many libertarians agree that paternalistic laws of this sort may be justified for minors, who often lack the experience and knowledge to make responsible decisions about their own well-being. But wisdom and immunity to peer pressure do not magically ignite at 18. 10/
On what grounds might such laws be justifiably applied to mature adults? During a sabbatical year I spent in France, I worked with a colleague who rode helmetless though heavy Paris traffic during her 45-minute daily bicycle commute to our office. 11/
When I once teased her about how concerns about fashion prevented her from wearing a helmet, she took umbrage. And in fairness, she was in fact the least fashion-conscious of the researchers in our office. 12/
A few weeks later, however, she told me about having tried on some bicycle helmets at Galeries Lafayette over the weekend. She confessed sheepishly that, on seeing herself in the mirror, she realized instantly that she would be unwilling to be seen in public wearing one. 13/
Whether wearing helmets seems unfashionable depends on how many other people are wearing them. When a cyclist rides without one, she contributes—albeit imperceptibly—to the impression that wearing a helmet is unfashionable. 14/
Some might object that people have agency, that is not government's job to protect people from their inability to resist peer influences. A fair point, but what about the injury to parents and others who care about those who take imprudent risks? 15/
A cyclist's choice thus entails not only potential harm to herself, but also harm to others who have no recourse. From the perspective of society as a whole, her own personal cost-benefit analysis makes riding without a helmet seem misleadingly attractive. 16/
This way of framing the problem suggests that the most straightforward remedy is not to mandate helmets, but rather to make riding without one less attractive. 17/
For example, we could permit someone who wants to ride with the wind in his hair to pay a modest annual fee for a medallion that, when affixed to his cycle, would entitle him to ride legally without a helmet. 18/
People for whom riding without a helmet is really an essential part of their cycling experience might find it worthwhile to pay this fee. But those who feel less strongly—in most cases, a substantial majority—would elect not to. 19/
And once enough people were seen with helmets, wearing one would no longer seem distressingly unfashionable. An added bonus is that each dollar collected from the fee would mean one dollar less that would need to be collected from taxes on beneficial activities. 20/
We could reduce the payroll tax, for example, which discourages firms from hiring additional workers. 21/
Allowing people to purchase the right to ride without a helmet is not a perfect solution, but it’s far less intrusive and more flexible than mandating helmets for everyone. 22/
Or so I argue in UNDER THE INFLUENCE: PUTTING PEER PRESSURE TO WORK, which describes how harnessing the prodigious power of behavioral contagion can help solve the most pressing problems we face, chief among them, the climate crisis. 23/
amazon.com/dp/B07XKFLWCT/…
amazon.com/dp/B07XKFLWCT/…
This well-crafted PBS NewsHour segment provides additional information about what’s inside the book: 24/
