It’s fitting that the sixth deadly sin of personal finance would be this one, after making a case for adequate insurance in the 5th deadly sin . Sometimes, in the quest to be frugal, we make decisions that can be short-sighted. These decisions, which may be beneficial in the short run, end up costing us big dollars in the long run because of unintended consequences or unforeseen circumstances. This is why the sixth sin of personal finance is …
Being Penny Wise, Pound Foolish
The simplest and most relatable example I can think of is buying 12-packs of Diet Coke at the super market. At normal prices, a 12-pack costs about four bucks a piece, for a unit price of thirty-three cents each. When it’s on sale, you can get a 12-pack for only $2 a piece (5 for $10 deals in the summer happen about once a month). I would only buy packs when they were at the $2 price… and then find myself spending $1.39 for 16 oz. bottles whenever I had an urge for Diet Coke. Penny wise… pound foolish.
That was a simple example, how about a more realistic one? Let’s say you’re a young professional looking to buy a car and trying to find easy ways to some extra money. You stumble onto my post about credit card offers  and think about signing up for a few cards for their bonuses. Bad idea. In the short term, you might get a few hundred bucks signing up for cards and spending the required amount but in the long term, you lower your credit score. That lower credit score will result in a car loan with a high interest rate. If you’re planning on buying a house in the next year, avoid these types of things!
Finally, here’s one that I grappled with while I was in school: working during college. My dad and I often discussed whether I should work while I was in college. His reasoning was that I was going to school to get a degree, not to work a part-time job that would distract me from the primary goal. I understood my Dad’s position, why work for $10/hr when I was paying $30,000 a year for tuition?
But I was impetuous and eager to earn my own way in the world, so I took some odd jobs and did some things on the side. Fortunately none of the jobs ever detracted from my study time (while my grades weren’t stellar, I could claim graduating early which saved a good chunk of change) but it could have. While I’m not saying you shouldn’t work in school, make sure you’re working for the right reasons. Working at a research assistant in your field of study is a smart move, working anywhere because you need the money to pay for school is a smart move, working at the local coffeehouse so you have some beer money is probably not the best.
To make sure you’re not committing this deadly sin of personal finance, weigh both the long term and short term impacts of the decisions you’re making. You don’t want to be too heavily emphasized in either direction.