My last post laid out data collection and methodology to determine the probability that an American will be injured or killed by an Islamic terrorist. The answer was, based on the most previous seven years of data, you would have to live about 10,000,000 years in order to have about a 90% chance of  falling victim to Jihadist terror. This number is given the assumptions that all other factors remain constant.

If you’re interested in the methodology and the math, check out the post.

But a common criticism of this model is that I left out the 9/11 attacks. Surely they will skew the y-axis, but it’s not in good form to ignore data points. I left these out for a couple reasons. First, the 9/11 attacks were sufficiently in the past. But more important, terrorists are no longer spending $500,000 to plan single, spectacular attacks. They are going cheap. Even bombings are going out of style. Kalashnikov rifles and stolen trucks are much more in vogue. I find it unlikely we’ll see another 9/11-style attack (even dirty bombs are quite meaningless in terms of casualties, which will probably be the 3rd part of this series).

So I repeated the methodology, this time capturing the previous 20 years of data, picking up casualty figures for 9/11. I ran the same simulation, and my results are not that much different—relatively speaking, of course—from my first simulation.

Results

In order to approach a 90% chance of falling victim to Jihadist terror in this updated model, you will have to live about 1.5 million years. The number we’re really interested in is 50%. To have a 50-50 shot of becoming a victim, you’ll need to live about 480,000 years. But remember, this model assumes there will be a 9/11 style attack every 20 years or so, so this number is probably hugely inaccurate. Personally I feel more comfortable with the first version of the model.

Either way, the probability of being injured or killed by an Islamic terrorist in the US during your lifetime is extraordinarily low. Of course these numbers are not meaningless when they aren’t zero. When the chance of being murdered is more than zero people respond in predictable ways, even if you’re more likely to win the lottery.