You Won’t Get Fooled Again: Understanding the Availability Heuristic in Investing

Originally in ForbesYou’re no fool. But let’s imagine for a second that a major public figure said something—something false—over and over (and over) again. Regardless of its questionable veracity, is there a chance you’d be more likely to believe the proclamation simply because you’ve heard it often and recently?

Like it or not, the answer is an emphatic “Yes.”

You and I are more likely to believe something is true when it’s readily available—that is, when we’ve heard it frequently and, especially, when we’ve heard it lately. This phenomenon is dubbed the “availability heuristic,” and even though it was discovered and named (by Amos Tversky and Daniel Kahneman) more than 40 years ago, it likely hasn’t caught on in the broader public awareness because its title includes the word “heuristic.”
Nonetheless, the availability heuristic’s power to persuade is not lost on marketers, salespeople, lobbyists and politicians. They use it on us all the time. But let’s explore the errant biases in investing, in particular, that while readily available often lead to sub-optimal outcomes.

Active vs. Passive

The debate rages (and no doubt will continue to do so) over whether active stock pickers are able to beat their respective benchmark indices. The implications seem simple: If fee-charging money managers aren’t persistently outperforming their benchmarks, we likely should not be paying them for underperformance, right?