No one likes the feeling of being indebted, whether it’s actual debt (student loans, mortgages, credit card…), or more generally in the sense of feeling an obligation to return some favor. And as this opening observation demonstrates, the decision of whether to pay down debt is often as much one of emotion as it is cold financial math. Therefore, answering the question of whether I should pay down my mortgage early or try to invest the savings in the market requires looking at both the math and the emotion of debt.