A reputable investment bank approaches you and says they’ll lend you as much money as you want for a very low interest rate. The rate depends on how long you want to hang onto the cash:

• 1 Month will cost you 0.01% APR interest
• 6 months: 0.07%
• 1 years: 0.11%
• 5 years: 0.88%
• 10 years: 2.02%

If you earn 3.5% on the money over 5 years which simply keeps pace with US inflation, when you pay back the principle you will be able to keep a 2.62% annual return on whatever you borrowed, based on the 5 year borrowing rate above. So if you borrow 1 million over 5 years you earn $138,046.62 in pure interest over 5 years (compounded annually).

Sounds like a pretty good deal right? $138K earned 5 years from now for nothing. I’d take it, assuming I could find somewhere to invest the money that would give me a 3.5% return, which shouldn’t be too hard.

However, if I’m fiscally irresponsible and rather than investing the cash I’m likely to spend it on hookers and blow, then it’s probably a bad idea for me to borrow as much as I can.

However, if I am that irresponsible and have a history of being a nut job, the interest rate that the investment bank charges me on my borrowings will reflect my lifestyle and will be more like 30% APR which is what many credit card companies charge once you’ve missed a payment.

The interest rates above are what America currently pays to borrow money. It’s the treasury yield curve rates. They are below inflation which means that the rest of the world pays the United States to store their money. And the United States makes money if they can get a very moderate return on any of that cash they invest. If the return simply keeps pace with inflation, they’re rolling in dough.

The interest rate the United States gets charged reflects how investment banks, sovereign wealth funds, companies and individuals feel about the United States “lifestyle” or fiscal and monetary level of responsibility.

So the question is: Can our country borrow trillions of dollars, put it to work in a responsible way and make out like a bandit? Or will it spend it all on hookers and blow and leave our grandkids in the hole struggling to pay off the principle?

Footnote: The answer to this question is usually along ideological lines. Keynsian economists like Paul Krugman who dominate the Democratic party will say Hell Yes! Government knows best and should borrow like there’s no tomorrow. Hayekian economists like Russ Roberts and economic conservatives on the other hand will tell you that the private sector knows best, government should limit it’s size and balance sheet and should never engage in massive borrowing no matter how low the interest rate or the potential return on investment, because it’s not government’s place to act like an investment bank.

Footnote2: I’m still feeling pretty good about my bull market prediction yesterday and am now long Apple (AAPL). I’m expecting it to churn during the next 6 months and have a 18 to 24 month price target of $550 (bought at $418).