It is commonplace to say that the pace of technological change is speeding up. From Twitter to online shopping our everyday lives are, apparently, being transformed.
One of the central puzzles of modern economics is that this change is not being seen in the hard economic data. Throughout the West rates of GDP and productivity growth have slowed in the last 20 years. If the official data are right, the great digital revolution is having surprisingly little effect on prosperity.
The great inventions of the past, such as the steam engine and electricity, changed lives and raised growth. Their modern counterparts seem to be changing lives – the media and most of us can hardly stop talking about them – but not GDP.
One explanation is that the GDP data are right and our impressions are wrong. The US economist Robert Gordon believes that the impact of today’s innovations on human welfare are trivial compared to the great innovations, such as indoor plumbing and antibiotics, of the past.
A more optimistic explanation is that technology is raising welfare, but in ways that are not captured by conventional measures of economic activity. On this argument GDP underestimates the full benefit to consumers of today’s technology.
GDP relies on the prices of goods and services to measure value. But many of today’s technologies are, in part or in full, free, paid for by advertising, monetising consumer data, patient investors or created by fellow users. The benefits we receive from, for instance, Google Maps or TripAdvisor, are not fully captured by today’s measure of GDP.
The unmeasured gain to welfare is known as the consumer surplus. It represents the difference between what a consumer pays and what they would have been prepared to pay for the good or service they use. Because consumers obviously only buy goods and services that deliver net benefits – where the value to the consumer exceeds the cost – the consumer surplus is always positive.