investigation of the effects of price change upon
the distribution of the product. However, large and protracted changes
in the price level do occur, and these are genuinely important factors
in the distributive outcome.

A study of the major price movements of the past makes clear the chief
characteristics of these large and protracted changes in the price
level. They are irregular changes. That is to say, all of the individual
prices which make up the price level do not change at the same time, nor
to the same extent. Certain prices may even change in opposite
directions.[38]

It is well to mark also, in passing, that the prices of some or many of
those articles which occupy a very important place in all calculations
of the cost of living of the wage earners--the articles of food and
clothing, and shelter--may change in a different measure, or even in a
different direction from the prices of the other commodities which
compose the general price level. This possibility is the most genuine as
regards food prices. Movements of food prices, and, indeed, of the
prices of all agricultural products, are apt over short periods to be
determined by weather conditions rather than by the industrial events
which govern the general price movement. Mr. W. C. Mitchell in his book
on business cycles studied the relation between the movements of retail
food prices (the figures ordinarily used in cost of living
investigations) and general business conditions during the 1890-1910
period in the United States. He writes in conclusion that "these figures
(i.e., of 30 retail food prices) indicate a certain correspondence
between retail prices and business conditions. In 1893, indeed, the
thirty foods rose slightly instead of falling, but they declined during
the dull years which followed the panic, and rose again when prosperity
returned. The rise was slow until 1900-02; it became slow again in
1902-04; but rapid in 1905-07. The panic of 1907 came too late in the
autumn to exercise much influence upon the average retail price level of
that year. On the whole, this series reflects the course of business
cycles better than might have been expected. For the supply of
vegetables and animal foods varies in an arbitrary fashion determined by
the weather, and the demand for staple foods is less affected by
prosperity and depression than that for the more dispensable
commodities."[39] Even over periods of some duration there may be a
marked diffe