Work upon business cycles is progressing so rapidly in so many quarters that a manuscript falls somewhat behind date while it is passing through the press. As partial remedy, I add notes on a few developments of which I have learned too late for mention in the proper place. Before the volume reaches its first readers, doubtless I shall be wishing that I might supplement these addenda. Not all the omissions are items of recent date. Probably the most serious are matters of which I should have known long ago, but of which I am still ignorant.
A Russian paper by Albert Wainstein on Harvests, Meteorological and Economic Cycles, and the Problem of Economic Forecasting, Moscow, 1926, reviews the recent literature upon weather theories of business cycles. Among the contributions noticed is a series of articles, otherwise unknown to me, published by Axel F. Enstrëm in the Teknisk Tidskrift (Veckoupplagen), 1916. From the French synopsis of Wainstein's paper, supplemented by notes which Dr. Kuznets has made, I judge Enstrëm's investigations to merit more attention than they have received. By repeated smoothing and differentiation of numerous time series, most of which run back to 1830, Enstrëm finds non-synchronous cycles of 8 to 9 years in wholesale prices, crops, production, temperature and sunspots. Between sunspot and temperature cycles he gets a correlation coefficient of -.94. He attributes the lagging cycles in economic activities to the cycles in temperature, and believes that the sequences are sufficiently regular to afford a basis for forecasting economic cycles from solar observations.
In the new volume of Der moderne Kapitalismus, "Das Wirtschaftsleben im Zeitalter des Hochkapitalismus" ( Munich and Leipzig, 1927), Professor Werner Sombart gives a fresh exposition of his theory of business cycles, showing the relation between the factor which he stresses (the different conditions under which organic and inorganic goods are produced) and other processes.