DWD20200408

David's Time With Peter F. Drucker 2020.4.8 Similarly, since the First World War——and probably since 1900——the share of disposable income in the developed countries, but altogether in the world economy, that is being spent on commodities of all kinds has been going down steadily at the rate of one-half of one percent per annum compound——wartimes excepted. This has held true for both food and industrial raw materials. This has meant that since 1900, the prices of all commodities have trended downward over any period of time. And the trend is still downward. Mature or declining industries may turn around and again become growth industries. For, to repeat, few things are as important for a strategy——both as threat and as opportunity——as a change in the trend of the shares of disposable that such an upturn would represent. ——《Management Challenges for the 21st Century · Chapter2》(Peter F.Drucker,1999)