Of course it does. In many cases you end up with no way to make the good decisions effective. I've never been what you might call seriously poor but I was unemployed for a few months after university and while the state did pay me a small benefit and I am not a big spender I quickly reached a point where I couldn't afford to put petrol in my car (a very frugal Mini) and not long afterward could not afford bus fares. This constrains your life decisions like eating healthy food can be impossible to make not because you can't afford the food but because you cannot make the journey to the shop, buying a USD 50 dollar sofa can be can be difficult because you can't afford the fuel to travel around town looking for the bargain. Of course all these things can be done but they require a greater degree of organization of the poor than it requires of someone who already has all that he needs to just decide to buy something with money that doesn't matter. If you have a minimum wage job you will inevitably be more stressed and stress leads to bad decisions.

Except it probably does. There are a lot of research suggesting that being poor is stressful and mentally draining, rendering you more likely to make poor decisions.