Sometimes the invisible handwave is combined with the incentives argument to suggest that when the stakes are high and the choices are difficult, people will go out and hire experts to help them. The problem with this argument is that it can be hard to find a true expert who does not have a conflict of interest. It is illogical to think that someon

The Weber–Fechner Law holds that the just-noticeable difference in any variable is proportional to the magnitude of that variable. If I gain one ounce, I don’t notice it, but if I am buying fresh herbs, the difference between 2 ounces and 3 ounces is obvious.

Thomas Schelling in his wonderful essay “The Life You Save May Be Your Own.”

To write these questions, I first had to decide which of two ways to ask the question: either in terms of “willingness to pay” or “willingness to accept.” The first asks how much you would pay to reduce your probability of dying next year by some amount, say by one chance in a thousand.

Optimization + Equilibrium = Economics.

The second asks how much cash you would demand to increase the risk of dying by the same amount.

He did so by positing that people’s happiness—or utility, as economists like to call it—increases as they get wealthier, but at a decreasing rate. This principle is called diminishing sensitivity. As wealth grows, the impact of a given increment of wealth, say $100,000, falls.

Many years later Kahneman and Tversky would call this distinction “framing,” but marketers already had a gut instinct that framing mattered. Paying a surcharge is out-of-pocket, whereas not receiving a discount is a “mere” opportunity cost.

The fact that a loss hurts more than an equivalent gain gives pleasure is called loss aversion. It has become the single most powerful tool in the behavioral economist’s arsenal.