The math might add up, but this might still be wrong. 1. Not spending $5 on Starbucks every day changes other things. For example, the person might have a feel

The math might add up, but this might still be wrong. 1. Not spending $5 on Starbucks every day changes other things. For example, the person might have a feeling of "I'm being good by saving $5", and that feeling might lead to purchasing something else as a reward - dessert at lunch, or a more expensive vacation at the end of the year. 2. Someone that spends $5 on Starbucks every day gets something in return. Maybe they enjoy it so much it makes them more productive, or maybe they meet friends there which makes them happy, etc. Regarding the math, the SP500 might not make 11.3% annually forever. It's a relatively high-risk investment compared to other avenues. So it might not be the most fair figure to use in the article's argument.