Numbers in the News: End Foreign Aid, Save Economy? It Doesn't Add Up

March 6, 2011— -- Let me begin with the first of two simple tests. Below are three headlines. Before reading any further, think about them for a bit and note your response to them.

1. After the Packers' Super Bowl victory, an exuberant Aaron Rogers Shook Hands with Everyone in the Stadium.

2. Experts Fear Total US Housing Costs (Rents plus Mortgage Payments) Will Top $2 Billion in 2011.

3. Only by Completely Eliminating Foreign Aid Can We Eliminate the Deficit.

These are just three of countless headlines or pseudo-headlines I might have chosen, but there's no need to belabor my point. Many people will recognize what should be clearly wrong with them, yet many people will not.

I have no formal statistics on the percentages in each class, but it never ceases to strike me how much public misunderstanding of issues derives from not paying any attention to numerical magnitudes in news stories. For too many people, numbers are there to provide decoration, not information.

Of course, in the artificial context of this test, not paying close attention is quite excusable. These are not real news stories after all. In any case, here is a brief account of a glaring problem with each of the three headlines above.

1. Making a few assumptions and carrying out a rough calculation shows that this story has to be bogus.

Any reasonable guess about the stadium capacity would be somewhere between 40,000 and 100,000, so let's say the stadium holds 70,000 or so people.

If they were all perfectly disciplined and lined up and proceeded past Rogers at a steady rate of 20 people per minute, the time needed would be 70,000 people/20 people/minute, or 3,500 minutes, or 58 hours or, assuming an 8-hour hand-shaking day, more than a week.

The hand-chafing that would result might be enough to end Rogers' passing career.

2. Again, a little arithmetic shows the headline to be absurd.

There are approximately 300 million Americans, which translates into very roughly 100 million households. Dividing $2 billion by 100 million households yields an annual expenditure per household of about $20.

Nothing to fear about paying only $20 annually for housing! Most people I've tricked into responding to this story talk about the mortgage crisis or housing prices and don't seem to notice the $2 billion figure. As long as it's a big number, they probably assume, it's OK.