We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run.

Towards the end of 1999, my boss was going to have breakfast with Bill Gates – no doubt alongside a few dozen others.  My contribution to this momentous event was to read Business @ The Speed of Thought:  Succeeding in the digital economy, which had been published under his name not long beforehand, and to provide a short summary.

One of the lines which stuck in my head was this:

We always overestimate the change that will occur in the next two years and underestimate the change that will occur in the next ten. Don’t let yourself be lulled into inaction.

As far as I recall, the thought wasn’t attributed to anybody else, but it also didn’t feel entirely original.  It was only last month that I came accross the version at the top of this post, much cited as a result of the death of Roy Amara, long-time leading light of the Institute for the Future.  I can’t immediately find a source which gives a date for Amara’s line – but even if he didn’t say it first, he said it in the context of a rigorous approach to conceiving the future which has been hugely influential, and probably deserves to be more influential still.

Update:  Since writing this I have come across Rex Hammock’s account of the history of this idea, in which he quotes Paul Saffo saying,

The idea that we overestimate short-term effects and under-estimate long-term implications of emergent technological change comes from an observation of the last 100-odd years of technology diffusion. As best as I know, Roy Amara, IFTF’s first president, was the first person to explicitly note this phenomenon, and thus at IFTF, we often refer to it as Amara’s law. I started talking about it publically in 1985, and Roy had been talking about it for at least 10 years before that.