Human beings are not equipped for dealing with large numbers. Honestly, 7 thousand, 7 million, 7 billion and 7 trillion all register about the same in my mind, namely 7 big. Unfortunately, there is a world a different between each of these, three whole orders of magnitude, a thousand, the difference between lifting me and a US quarter.
This lack of respect for orders of magnitude has really been rearing its head recently with most of the political discussions surrounding the US budget.
Turns out the US Budget is really large. In 2010 it weighed in at $3.55 trillion. Thats big. Really big. So big that I can't fathom it.
Without getting too political, there has been a site going around recently; the
You Cut program, which invites public suggestions for cuts to be made to the budget to try and fix the deficit. Now, personally, I believe we ought to do something about the deficit. To this end, I think it is useful to point out the scales involved. In particular, the link I gave above is to one of the suggested cuts: federal funding of NPR (Disclaimer alert: I love NPR), which weighs in at 7 million dollars.
Seven million dollars is a lot of money. A lot of money, more than I can imagine having personally. But to suggest that a 7 million dollar cut is any sort of progress towards solving a $1.2 trillion dollar deficit is a little amusing. As a fraction, this comes out to
\[ \frac{ 7 \text{ million} }{ 3.55 \text{ trillion} } = 2 \times 10^{-6} \]
Two parts in a million. To give a sense of scale to this, the gravitational influence of the moon on my weight is:
\[ \frac{ \frac{ G M_{\text{moon}} }{ R_{\text{earth-moon}}^2 } }{ 10 \text{ m/s}^2 } = 3 \times 10^{-6} \]
Three parts in a million. So, suggesting that you have made real gains in reducing the US budget by cutting federal funding for NPR is as silly as suggesting that if I want to lose weight, my first concern should be the current tides.
[I want to point out that I don't really mean to get too political, and that I've noticed both parties pulling these kinds of numbers tricks.]
So, wanting to get a little better understanding of the numbers at stake, I collected some data (all from the 2010 budget). My goal is to attempt to represent how the US government spends its money.
Before I begin I need to plug two great tools towards this end:
Here the NYTimes graphically represents government spending, helping to give a sense of scale to different categories.
Here the NYTimes lets you try and balance the budget, not only for next year but down the line, letting you choose from a wide array of proposed changes.