Page:Popular Science Monthly Volume 39.djvu/463

Rh of the statistical mechanic—the man who is ready at all times to construct tables showing such points as may be ordered of him. This latter person is a nuisance. He perverts facts and shows how to reach conclusions false in themselves by the use of truthful statements. Some practical illustrations drawn from actual experience may be of value, and show how we can guard against vicious conclusions when the statistical statements from which the conclusions are drawn are true. This method will also show the true value of statistics.

I have seen it argued that the production of cheese in the United States is growing smaller and smaller, and is likely to cease entirely. This argument is based upon the following figures, taken from the agricultural statistics of the Federal censuses of 1850, '60, '70, and '80: The production of cheese, according to such statistics, was, in 1850, 105,535,893 pounds; in 1860, 103,663,927 pounds; in 1870, 53,492,153 pounds; and in 1880, 27,272,489 pounds. Nothing could be more conclusive as evidence than these figures, because, while the statement for 1850 might be erroneous on account of imperfect enumeration, the enumerations have grown more and more complete; and if the 1880 figures show only about one quarter of the product of 1850, the cheese industry must soon cease to exist. A very little study and a very small amount of common knowledge would have taught the one using the argument I have quoted to examine the statistics of manufactures, as the production of cheese has been thrown largely into the factory. By consulting this side of the census, it is found that the production of cheese in factories in 1880 was 171,750,495 pounds; the truth being, therefore, that the production of cheese in the United States is, as one would naturally suppose, largely on the increase.

One of the most common statistical illustrations used in political arguments is that relating to the percentage of increase of population as compared with the percentage of increase in expenditures. I have prepared a little table (which I have never seen in print) showing the factors used in such an argument, supplemented by factors which ought to be used. The table is as follows: