[greenleafjacob]

It's not wrong, but think of it this way: if you short a stock, your downside exposure is unlimited because the price can go arbitrarily high, but your upside is finite because the stock can only go to zero. In the same way, you can only decrease your spending so much, even to zero, but you can increase your income by an unlimited amount.

[ericd]

Yep, you're right. For many people, though, increasing their income substantially is harder than decreasing their spending substantially, and also, many people are in the habit of increasing their spending when their earnings increase by, say, switching from Ikea to higher end furniture, or trading in that used Honda for a new Mercedes. For many people, it's so bad that they end up not saving any more, while putting themselves in a more precarious position if their income ever dried up.