Paul Krugman opines on the fiscal cliff, and why machines may replace humans.

If you follow these things, you know that the field of artificial intelligence has for decades been a frustrating underachiever, as it proved incredibly hard for computers to do things every human being finds easy, like understanding ordinary speech or recognizing different objects in a picture. Lately, however, the barriers seem to have fallen — not because we’ve learned to replicate human understanding, but because computers can now yield seemingly intelligent results by searching for patterns in huge databases.

True, speech recognition is still imperfect; according to the software, one irate caller informed me that I was “fall issue yet.” But it’s vastly better than it was just a few years ago, and has already become a seriously useful tool. Object recognition is a bit further behind: it’s still a source of excitement that a computer network fed images from YouTube spontaneously learned to identify cats. But it’s not a large step from there to a host of economically important applications.

So machines may soon be ready to perform many tasks that currently require large amounts of human labor. This will mean rapid productivity growth and, therefore, high overall economic growth.

But — and this is the crucial question — who will benefit from that growth? Unfortunately, it’s all too easy to make the case that most Americans will be left behind, because smart machines will end up devaluing the contribution of workers, including highly skilled workers whose skills suddenly become redundant. The point is that there’s good reason to believe that the conventional wisdom embodied in long-run budget projections — projections that shape almost every aspect of current policy discussion — is all wrong.

What, then, are the implications of this alternative vision for policy? Well, I’ll have to address that topic in a future column.

In the past, Krugman has written about the danger of outsourcing legal jobs. I, for one, am not worried about our new robotic overlords.