Author Archives: Matthew Green

Economic growth is at the heart of the current political debate. And yet growth is a complex aggregate statistic, and few people take the trouble to pick apart what is actually happening to it, as opposed to speculating what in theory might be happening. That has created a vacuum into which think tanks, economic commentators and politicians project their own hobbyhorses without fear of serious challenge. So what really is going on?

The main mistake people make is to assume that the main driver of growth is productivity. This is exemplified by the famous quote from American liberal economist Paul Krugman: ”Productivity isn’t everything, but in the long run it is almost everything.” Cue a furious debate on a “productivity puzzle” or “gap”, especially here in Britain – supported by  unreliable productivity measurements. Productivity is such a heterogeneous and hard-to measure phenomenon that measurements depend heavily on assumptions – and it is hard to understand their significance anyway. Prior to the crash, for example, improvements to Britain’s measured productivity depended almost entirely on two narrow sectors: financial services, whose profits proved largely illusory, and “business services” a shadowy sector the real value of whose output is hard to be sure of.

But help is at hand. American economist Dietrich Vollrath decided to pull apart growth figures to settle the debate on why American growth had slowed so much in the 21st Century compared to second half of the 20th – this debate isn’t just a British thing. As it happened, he had his own hobby horse which he was convinced was behind the issue – the growing market power of large companies. Vollrath found that two thirds of the decline in growth rates (1.25% per annum per capita at the time he was doing the work – a very similar figure to the UK) was down to demographics – the proportion of working people to the population as a whole, which has been declining as the dynamics of the baby boom work themselves out. Nearly half of the rest was down to what economists call the “Baumol effect” – named after an economist who pointed out that increases in productivity lead to a shift to economic sectors with lower productivity. As we get more efficient at making mobile phones, for example, we don’t buy more mobile phones – we spend the surplus on things like healthcare or designer clothes instead. Incidentally, he found little evidence that his own hobby horse, market power, had much effect, and none that tax changes and deregulation did – except changes that restricted worker mobility, and especially restrictions to house building. He called the two principal phenomena the problems of success and published his findings in a book: “Fully grown: Why a Stagnant economy is a Sign of Success.” This was rated as one of The Economist magazine’s books of the year for 2020, though its writers have failed to take its findings to heart.