Can we trust the population experts?

No doubt there have always been people curious about what the future will bring and other people willing, for due reward, to satisfy their curiosity.
 
Before our era the foretellers of the future—the prophets, the oracles, the astrologers, the fortune-tellers and palm readers—claimed some special inspiration; nowadays the role has been largely taken over by the politicians and newspapers, who in turn rely on the scientific experts. In a period of about a hundred years their expertise has been more and more supported by the mass of statistics produced mainly, but not entirely, by government departments. And this statistical material is popularly, but quite erroneously, accepted as giving additional authority to the forecasts.
 
Recently the Tory Government issued a White Paper indicating how the amount of Government expenditure will increase some years ahead, backed by figures; but this is no more reliable than the Tory statement at the 1951 election that they were appalled by the way the Labour Cabinet had increased government expenditure arid would cut it down; a promise completely falsified by events. No government knows what situation it will be dealing with in five years’ time; nor do the statisticians.
 
There is a famous saying that figures can’t lie but liars can figure. Whoever said this was worrying about the wrong thing. It isn’t so much the liars who feed us wrong information about the future as the confident “experts” who believe they are speaking the truth. Nowhere has this been more glaringly shown than in the field of forecasting the size of the population.
 
Probably there were people in this country about the year 1330 who went around saying that the population would be much larger twenty years ahead, not knowing that the Black Death would wipe out a third or more of them. They did not have the benefit of statistics about the way the birth rate and death rate had been moving in past years, but it wouldn’t have made their forecasts any better if they had. Our modern experts have not even the excuse of a major calamity to explain theirs.
 
About the beginning of the 19th century quite a lot of the economists shared the view of Malthus about the need to restrain the birth rate because of the supposed inability to provide rapidly growing supplies of food; they failed entirely to foresee the enormous growth of population that took place during the century and before long their views were discredited and largely forgotten.
 
Just a century later the Malthusian view had a rebirth with Keynes and other Cambridge economists. Keynes started it in his Economic Consequences of the Peace, published in 1920. He feared that overpopulated Europe could no longer feed itself and was faced with a declining standard of living. Other books were published surveying the problem and suggesting the need to seek a solution in a smaller and stable population. Among these was Population, by Harold Wright, with a preface by Keynes (1933).
 
Although there were other economists, including Cannon and Beveridge, who contested the Keynesian view, it became increasingly the fashion in the nineteen-thirties to predict that the population of this country would rise for a few years and then go into a decline. Some of their predictions were published in a book called The Home Market, 1939, which had the unintentionally ironical sub-title, A Book of Facts about People.
 
The purpose of the book was to enable manufacturers to know what size they might expect their potential market to be in the years ahead so that they could plan accordingly. It had a foreword by Mr. Frank Pick, Vice-Chairman of the London Passenger Transport Board, who saw in the provision of information the means of avoiding “lack of balance between supply and demand.” (Can it be that this may have been responsible for the deficiencies of transport in London?).
 
The book’s population estimates were those of Dr. Grace Leybourne, but readers were assured that similar estimates had been made by Dr. Kuczynski and Dr. Enid Charles, two other authorities. And what did the stars foretell? The population (excluding Northern Ireland) was then about 46,350,000. The forecast was that it would reach a peak of 46,500,000 in 1941, and then drop by 4 millions to 42,700,000 in 1951 and by another 3 millions to 39,400,000 in 1961.
 
In fact the population (again excluding Northern Ireland) had reached 51,350,000 by 1961. Instead of falling by 7 million after 1941 it had gone up by about 5 million!
 
They also tried their hand at foreseeing changes in the age group. They were right about the increase in the proportion over age 65, but quite wrong about the numbers of children. They thought that the number of children under 15 would have dropped in 1961 to 5½ million: it actually turned out to be 12 million.
 
If perhaps London Transport were misled by the pre-war experts as to the likely size of the travelling public in London, the Education authorities must have been shattered to find that they had to provide for double the number of school children the experts expected.
 
After the war the government set up the Royal Commission on Population which in its report in 1949 was very cautious about the future, merely saying that the total population would probably go on growing for at least one or two decades, “though the increase in this period is not likely (immigration apart) to exceed more than a few millions.” (Para. 632.) The Government then entered the tricky field of forecasting future population itself, but it hasn’t been any luckier than the experts of “private enterprise.”
 
It started in the 1956 edition of Annual Abstract of Statistics, in which it estimated that the population (excluding Northern Ireland) would be 51,796,000 in 1960. The actual figure for 1960 turned out to be 587,000 higher than the estimate. Not perhaps a very big error, but large enough to cause headaches to anyone who made plans based on the smaller figure. As the Minister of Health recently complained, how could he be expected to build sufficient maternity accommodation when “the birth rate was rising more rapidly than any experts had foreseen.” Naturally the longer the forecast the larger the error may turn out to be.
 
In the 1956 edition of the Annual Abstract the population to be expected at the end of the present century was given as something under 53 million. But in the 1962 edition this had been amended to 68 million, a trifling 15 million more. They are not the first to risk forecasting how many people there will be in this country at the end of the century. A Fabian pamphlet, Our Ageing Population, published in 1938, opened by quoting an estimate of the Population Investigation Committee that if “there is no change in the present trend of the birth and death rates” the population at the end of the century will be 17,700,000!
 
So we are on firm ground at last. It will be 17,700,000; or maybe 53,000,000 or 68,000,000; or some other number, larger or smaller.
Edgar Hardcastle

 

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