The Back Half of the Chessboard

A nonmetaphorical chessboard.

Photo by Manan Vatsyayana/AFP/Getty Images

Robert Gordon continues to be unimpressed by the technological possibilities of the near future, offering this cranky observation about technological deployment:

What is often forgotten is that we are well into the computer age, and every Home Depot, Wal-Mart, and local supermarket has self-check-out lines that allow you to check out your groceries or paint cans by scanning them through a robot. But except for very small orders it takes longer, and so people still voluntarily wait in line for a human instead of taking the option of the no-wait self-checkout-lane. The same theme—that the most obvious uses of robots and computers have already happened—pervades commerce. Airport baggage sorting belts are mechanized, as is most of the process of checking in for a flight.

If you want a thorough explanation of why this is wrong, you should read The Second Machine Age from Erik Brynjolfsson and Andrew McAfee. But the most basic problem with this take has to do with a phenomenon  called “the back half of the chessboard,” which involves a literary reference that I don’t think you need to understand. The basic issue is that, per Moore’s law, computing power is growing at an exponential pace, not a linear one.

If you look at computers today, they are a lot more powerful than they were 30 years ago. They’ve gone from 1 to 2 to 4 to 8 to 16 to 32 to 64 to 128 to 256 to 512 to 1024 on my arbitrary doubling scale. That’s a lot of improvement—but the next doubling of computing power will take us from 1024 to 2048! In other words, more computing power will be added during the next two-to-three-year doubling cycle than has been added in the entire history of computing. And then that’s going to happen again. Unless you think about it in the correct exponential terms, you’re going to massively underrate the likely gains in the future. As it happens, I agree with Gordon that self-checkout technology is not incredibly promising but that’s because it addresses an uninteresting problem. What if you could automate grocery delivery? Or what if “the Internet of things” let you just put a bunch of stuff in your bag, walk out of the store, and then automatically have the cost tallied up and charged to your credit card? That’d be cool.