Willie Sutton Rule

The Willie Sutton Rule recommends starting with the most obvious, highest‑impact option when solving a problem: go where the rewards or answers are likeliest to be found. It is named after bank robber Willie Sutton, who reportedly replied “Because that’s where the money is” when asked why he robbed banks.

Core idea

• Prioritize obvious, high‑return opportunities or likely causes before exploring obscure or unlikely alternatives.
• Emphasizes efficiency: focus effort where the greatest results or savings are most likely.

Origin and related aphorisms

• Attributed to Willie Sutton’s reputed remark about robbing banks.
• Parallels Sherlock Holmes’ principle: eliminate the impossible and the remaining (however improbable) is the truth.
• In medicine the same principle is taught as “Sutton’s Law”: test for the most likely diagnosis first.

How it works in practice

• Identify the most probable source of the problem or the easiest path to gain.
• Allocate resources (time, tests, budget) first to options with the highest expected payoff or probability of success.
• If the obvious path fails, broaden the search to less likely causes or strategies.

Common applications

• Investing: pick straightforward, well‑understood opportunities (the “low‑hanging fruit”) before pursuing speculative or complex strategies.
• Management accounting: apply activity‑based costing and prioritize cost‑reduction efforts on the largest cost drivers to maximize savings.
• Medicine: order tests for common, likely diagnoses before pursuing rare conditions, reducing time, expense and unnecessary procedures.

Benefits

• Faster, often cheaper resolution.
• Higher probability of success by addressing the likeliest causes first.
• Better resource allocation and clearer decision‑making.

Limitations and cautions

• Can overlook low‑probability but high‑impact events (black swans).
• May encourage complacency if practitioners fail to revisit assumptions after initial efforts fail.
• Not appropriate when evidence suggests an uncommon cause or when the cost of missing a rare outcome is very high.

Practical tips

• Use probability and impact to rank options before acting.
• Define stopping rules: how long to pursue the obvious path before expanding the search.
• Reassess assumptions regularly and be ready to escalate to less likely explanations when warranted.

Takeaway

The Willie Sutton Rule is a pragmatic decision principle: start with the most obvious, high‑value options or diagnoses. It improves efficiency and often leads to quicker success, but should be balanced with attention to rare but consequential possibilities.