**TL;DR: Google is double-matching donations to fight ebola. If you donate $1, Google will donate $2.**

**Donation link: https://onetoday.google.com/fightebola**

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I know this isn't book-related, but as I’ve mentioned previously, of all the issues currently affecting the world, I think the one that I care about most--or at least see as the most actionable-- is the ebola crisis. Every time I see a US news article, it asserts that the “ebola panic” is a hysterical overreaction, I get a little more angry. **Why is the “ebola panic” groundless?**

**Because people aren’t dying in the U.S.**

**Apparently all those deaths in Africa just don’t count.**

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Why is acting now so important? Because the epidemic spreads *exponentially.*

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One way to describe the “infectiousness” of a disease is via its R0 (pronounced “R-nought”), which is, roughly, the number of people we expect an infected person to infect in turn.

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**If R0 is less than 1**, then on average, each person infects 0 or 1 people. Some people might infect more than one, but overall, there’s a pretty high probability that an infected individual won’t infect anyone else. Even if a lot of people start out infected, that sort of infection will die out on its own. For example, if we start out with 3 sick people, it might look like this:

And that's it. The infection dies out.

**But if R0 is greater than 1**, then each infected person spreads the infection just a little bit more. **Ebola’s R0 is between 1.7 and 2. **So on average, each person is spreading the disease to one or two new people. Say we start out with one infected person:

And on, and on, until some new factor slows down or stops the infection. The disease spreads *exponentially*.

But what if we could prevent that *first* person from getting sick?

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And that is why I think it is so crucial to help with the ebola crisis. I’m not “panicked” over the potential for infection in the U.S. I’m panicked over the potential for infection, period. And every person that we don’t help may get even more people sick, and they'll get still more people sick. If we help one person now, then we’ve cut off one of these exponentially-growing trees.

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Talk about impact.

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**Here’s the Google blog post, with links to the donation pages.**

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And here’s an article with prettier graphics than mine: http://www.economist.com/blogs/graphicdetail/2014/11/ebola-graphics