The Rational Optimist: How Prosperity Evolves. Matt Ridley

‘should not exceed…35 years at age 50 unless major breakthroughs occur in controlling the fundamental rate of ageing’. Within just five years both predictions were proved wrong in at least one country.

      Consequently the number of years of retirement is rocketing upwards. Starting from 1901, it took sixty-eight years for the mortality of British men between 65 and 74 to fall by 20 per cent. Subsequent 20 per cent falls took seventeen years, ten years and six years – the improvement has accelerated. That is all very well, say pessimists, but what about quality of life in old age? Sure, people live longer, but only by having years of suffering and disability added to their lives. Not so. In one American study, disability rates in people over 65 fell from 26.2 per cent to 19.7 per cent between 1982 and 1999 – at twice the pace of the decrease in the mortality rate. Chronic illness before death is if anything shortening slightly, not lengthening, despite better diagnosis and more treatments – ‘the compression of morbidity’ is the technical term. People are not only spending a longer time living, but a shorter time dying.

      Take stroke, a big cause of disability in old age. Deaths from stroke fell by 70 per cent between 1950 and 2000 in America and Europe. In the early 1980s a study of stroke victims in Oxford concluded that the incidence of stroke would increase by nearly 30 per cent over the next two decades, mainly because stroke incidence increases with age and people were predicted to live longer. They did live longer but the incidence of stroke in fact fell by 30 per cent. (The age-related increase is still present, but it is coming later and later.) The same is true of cancer, heart disease and respiratory disease: they all still increase with age, but they do so later and later, by about ten years since the 1950s.

      Even inequality is declining worldwide. It is true that in Britain and America income equality, which had been improving for most of the past two centuries (British aristocrats were six inches taller than the average in 1800; today they are less than two inches taller), has stalled since the 1970s. The reasons for this are many, but they are not all causes for regret. For example, high earners now marry each other more than they used to (which concentrates income), immigration has increased, trade has been freed, cartels have been opened up to entrepreneurial competition and the skill premium has grown in the work place. All these are inequality-boosting, but they stem from liberalising trends. Besides, by a strange statistical paradox, while inequality has increased within some countries, globally it has been falling. The recent enrichment of China and India has increased inequality within those countries by making the income of the rich grow faster than that of the poor – an income gap is an inevitable consequence of an expanding economy. Yet the global effect of the growth of China and India has been to reduce the difference between rich and poor worldwide. As Hayek put it, ‘once the rise in the position of the lower classes gathers speed, catering to the rich ceases to be the main source of great gain and gives place to efforts directed towards the needs of the masses. Those forces which at first make inequality self-accentuating thus later tend to diminish it.’

      In another respect, too, inequality has been retreating. The spread of IQ scores has been shrinking steadily – because the low scores have been catching up with the high ones. This explains the steady, progressive and ubiquitous improvement in the average IQ scores people achieve at a given age – at a rate of 3 per cent per decade. In two Spanish studies, IQ proved to be 9.7 points higher after thirty years, most of it among the least intelligent half of the group. Known as the Flynn effect, after James Flynn who first drew attention to it, this phenomenon was at first dismissed as an artefact of changes in tests, or a simple reflection of longer or better schooling. But the facts do not fit such explanations because the effect is consistently weakest in the cleverest children and in the tests that relate most to educational content. It is a levelling-up caused by an equalisation of nutrition, stimulation or diversity of childhood experience. You can, of course, argue that IQ may not be truly representative of intelligence, but you cannot argue that something is getting better – and more equal at the same time.

      Even justice has improved thanks to new technology exposing false convictions and identifying true criminals. To date 234 innocent Americans have been freed as a result of DNA fingerprinting after serving an average of twelve years in prison; seventeen of them were on death row. The very first forensic use of DNA in 1986 exonerated an innocent man and then helped to catch the real murderer, a pattern that has been repeated many times since.

      Cheap light

      These richer, healthier, taller, cleverer, longer-lived, freer people – you lot – have been enjoying such abundance that most of the things they need have been getting steadily cheaper. The four most basic human needs – food, clothing, fuel and shelter – have grown markedly cheaper during the past two centuries. Food and clothing especially so (a brief rise in food prices in 2008 notwithstanding), fuel more erratically and even housing has probably got cheaper too: surprising as it may seem, the average family house probably costs slightly less today than it did in 1900 or even 1700, despite including far more modern conveniences like electricity, telephone and plumbing. If basic needs have got cheaper, then there is more disposable income to spend on luxuries. Artificial light lies on the border between necessity and luxury. In monetary terms, the same amount of artificial lighting cost 20,000 times as much in England in the year 1300 as it does today.

      Enormous as that difference is, in labour terms the change is even more dramatic and the improvement is even more recent. Ask how much artificial light you can earn with an hour of work at the average wage. The amount has increased from twenty-four lumen-hours in 1750 BC (sesame oil lamp) to 186 in 1800 (tallow candle) to 4,400 in 1880 (kerosene lamp) to 531,000 in 1950 (incandescent light bulb) to 8.4 million lumen-hours today (compact fluorescent bulb). Put it another way, an hour of work today earns you 300 days’ worth of reading light; an hour of work in 1800 earned you ten minutes of reading light. Or turn it round and ask how long you would have to work to earn an hour of reading light – say, the light of an 18-watt compact-fluorescent light bulb burning for an hour. Today it will have cost you less than half a second of your working time if you are on the average wage: half a second of work for an hour of light. In 1950, with a conventional filament lamp and the then wage, you would have had to work for eight seconds to get the same amount of light. Had you been using a kerosene lamp in the 1880s, you would have had to work for about fifteen minutes to get the same amount of light. A tallow candle in the 1800s: over six hours’ work. And to get that much light from a sesame-oil lamp in Babylon in 1750 bc would have cost you more than fifty hours’ of work. From six hours to half a second – a 43,200-fold improvement – for an hour of lighting: that is how much better off you are than your ancestor was in 1800, using the currency that counts, your time. Do you see why my fictional family ate by firelight?

      Much of this improvement is not included in the cost-of-living calculations, which struggle to compare like with unlike. The economist Don Boudreaux imagined the average American time-travelling back to 1967 with his modern income. He might be the richest person in town, but no amount of money could buy him the delights of eBay, Amazon, Starbucks, Wal-Mart, Prozac, Google or BlackBerry. The lighting numbers cited above do not even take into account the greater convenience and cleanliness of modern electric light compared with candles or kerosene – its simple switching, its lack of smoke, smell and flicker, its lesser fire hazard. Nor is the improvement in lighting finished yet. Compact fluorescent bulbs may be three times as efficient as filament bulbs in turning electrons’ energy into photons’ energy, but light-emitting diodes (LEDs) are rapidly overtaking them (as of this writing LEDs with ten times the efficiency of incandescent bulbs have been demonstrated) and have the added benefit of working at a portable scale. A cheap LED flashlight, powered by a solar-charged battery, will surely soon transform the life of some of the 1.6 billion people who do not have mains electricity, African peasants