Changing rates of change

Compared to most times in human history, the present is clearly a period of exceptionally fast technological change. Some commentators have claimed that we see faster technological development now than ever before and that the rate is increasing exponentially—some (e.g., Ray Kurzweil) even predicting a “technological singularity” later in this century. Others (e.g., Vaclav Smil) are sceptical of this claim. Questions about growth rates matter because they lead to widely different predictions about how much change we can expect to see within our lifetime and how it will relate to other ongoing trends.

To even begin to address these issues, it is necessary to be more precise about what kind of change we are talking about and how it can be measured. Global economic productivity has indeed been growing exponentially for a considerable period of time, albeit with a much longer doubling time than Kurzweil seems to envisage. But to anticipate when we might see certain kinds of advanced technological applications or certain kinds of societal impacts, more domain-specific measures of the pace of innovation should be considered.