BOOK REVIEW Chris Johns A Farewell to Alms: a brief economic history of the world By Gregory Clark Princeton €29.95 (€22)Through his unorthodox analysis of the causes of Britain's industrial revolution, the author argues that economic success has to become part of our genetic make-up, writes Chris Johns

The industrial revolution and the first World War share a common characteristic: countless books have been written by historians, each with a unique explanation of why each of these rather important events occurred.

That so many people can have such different explanations is intellectually curious but not terribly helpful for those seeking to prevent future wars or encourage poor countries to become rich.

Gregory Clark has added another unique perspective. In trying to establish the causes of the industrial revolution, Clark, like most other well-intentioned authors, tries to infer what that might mean for modern-day countries stuck with medieval living standards.

Students of 18th-century England generally argue about the single biggest cause of what looks like a sudden leap from poverty to riches. It might have been the invention of the steam engine, the spinning jenny, or the benefits of a stable monarchy. Or all three and much besides. But most analysts seem to agree that something very discrete happened very quickly. The question that orthodox analysis seeks to answer focuses on the catalysts or drivers of that sudden change.

Clark disagrees. Up until 1800, he suggests that England, and pretty much everywhere else, was stuck in a "Malthusian trap", whereby any economic improvements were quickly dissipated by population growth such that per capita living standards were not that different from the Stone Age. He presents an impressive range of data demonstrating this extraordinary fact: someone alive in 1800 was, on average, not materially better off than someone living in a cave during prehistoric times.

"Averages" can still conceal a lot of variation: in 1800, the average Englishman was richer (and bigger) than his average Chinese counterpart. Clark's explanation for such differences is as interesting as it is odd: "the relative wealth of the English . . . matched against the Chinese . . . probably stemmed mostly from the relative filth in which they wallowed".

Living in squalor prevented population growth: the cleaner Chinese, with better mortality and demographics were, as a result, deeper into the Malthusian trap. There were more of them and they therefore each took smaller slices of the pie. You might have lived like a pig in England but the contents of your trough were of a slightly higher standard.

Clark rejects the idea that something big happened to spur the industrial revolution. He doesn't even like the label "industrial": he reckons the gains to agricultural productivity were just as significant as the move into factories. Essentially, Clark believes that the seeds of the revolution were planted over many centuries. It was all about the establishment of middle-class values like thrift, hard work and, intriguingly, the downward socio-economic mobility of those middle classes.

In pre-1800 England, the only people with large families were the rich. Malthusian forces meant that poor people either didn't have children or, if they did, they didn't live for very long. But those fecund middle classes couldn't keep their children in the style of the parents. Malthusian logic forced them down the income scale, and that meant middle-class ethics and values spread to the lower classes.

This gradual process made a huge contribution to what eventually looked like an industrial revolution but wasn't really. In this sense, Clark is an evolutionary biologist: economic success has to become part of our genetic make-up.

Clark, inevitably perhaps, uses all of this to have a go at the current "Washington consensus" (code for International Monetary Fund and World Bank policies), which argues, among other things, for liberal capitalism, low taxes and small government as the route for the Third World to develop. Pushed to his logical conclusion, he might argue that, if we want Africa to become rich, it needs first to grow a middle class and wait 500 years for their values to become embedded in the population as a whole. He doesn't go this far, of course, but the reader is left to wonder.

All of this is great fun. It is new and makes great use of untapped data sources. But is it convincing? Just as we are still none the wiser about the actual causes of the first World War, despite all the effort put into their discovery, I suspect that we will never know what caused the industrial revolution. It may be that Clark's evolutionary biology was a factor, but surely that doesn't rule out sudden technological discoveries, temperate climates and the stability of English political institutions.

Perhaps complex phenomena have lots of drivers. And, more importantly, economic success may not have a unique set of drivers. The English did it 200 years ago in one way; the Chinese have been doing it more recently in their way.

This is not a book that orthodox economists will like. It is well written and superbly argued. At the end of the day it is pessimistic. There are many people in India and China who will cheerfully disagree.

Chris Johns is head of global research and equity portfolio management at Bank of Ireland Asset Management