When we see people making bad decisions – whether as consumers or voters – we often blame the “complexity” of the issues they face. If Ph.D. economists can’t figure out the best mortgage to use, how can we expect the average borrower to do so? If health policy experts can’t agree on how to fix the U.S. medical system, what is the typical voter to think?

But if complexity is your only demon, I’ve got two simple rules of thumb to exorcise him. Here goes:

1. If you don’t have clear and convincing evidence that doing something is better than doing nothing, do nothing.

2. If you know that doing nothing is bad, but don’t have clear and convincing evidence that one action is better than another, do the simplest, standard thing.

I frequently apply these rules to my consumption decisions. Until I’m convinced that a product will make my life better, I just don’t buy it. I might enjoy a big plasma T.V., but until a seller clearly explains how he’s going to painlessly install it in my house, I’m not buying one. If I do decide in favor of a plasma T.V., but remain confused about which one to buy, I’ll probably just get the biggest one that CostCo carries.

In the mortgage market, similarly, my heuristics say: (a) Rent until it’s clear that buying will improve your life; and (b) Get a standard 30-year fixed-rate mortgage from an established lender. Don’t buy a house you might not be able to afford by signing a contract you can’t explain to your friends.

Needless to say, voters could also use these heuristics to decide which policies to support. Until there’s clear and convincing evidence that health-care reform or invading someone will make things better, you’re better off saying No. And if you are convinced that “doing something” is better than “doing nothing,” your best bet is to go with the simplest, standard option.

Admittedly, that last sentence of advice makes me a little uncomfortable. Many policies I detest – like immigration restrictions – are nevertheless simple and standard. But overall, I’m not too worried about the political consequences of my rules of thumb. If votes just learned to say No until a politician could clearly show that government action would improve the world, voters would shout down most of the policies I detest before they ever got to my second heuristic.