Exercise 3: What "Objectively Worse" Misses About the Snowball Method — Possible Solution ==================================================================== The friend's claim treats "mathematically optimal" and "actually works for real people" as the same thing, but the chapter's own real research finding shows they can genuinely diverge. The debt avalanche method does minimize total interest paid, which is a real, correct mathematical fact - but the 2012 Kellogg School of Management study found that people using the snowball method were genuinely more likely to actually eliminate their overall debt than those using the mathematically superior avalanche method. A repayment strategy only produces its real benefit if someone actually follows through with it to completion - a mathematically optimal plan that gets abandoned partway through produces worse real results than a mathematically suboptimal plan that gets finished. The smaller, faster wins the snowball method produces appear to sustain real motivation better for many people, which is precisely the kind of behavioral factor the friend's "no rational person" framing leaves out entirely - it isn't irrational to choose the option genuinely more likely to actually work for you, even if it isn't the option that looks best on paper alone. ANSWER: This claim misses that the chapter's own real 2012 Kellogg study found snowball users were more likely to actually eliminate their debt than avalanche users, despite avalanche being mathematically optimal - a plan only produces its benefit if someone follows through with it, and choosing the strategy more likely to actually be completed isn't irrational, even when it isn't the mathematically optimal one. WHY THIS WORKS AS AN ANSWER ------------------------------ This correctly reproduces the chapter's own real, counter-intuitive research finding to explain why "mathematically optimal" and "objectively best for a real person" aren't automatically the same claim, rather than accepting the friend's assumption that they are.