This essay discusses predecessors of long ago, and the 1950s and 1960s, who studied the effects of population change. The history is not systematic, but rather is idiosyncratic. It focuses on the valuable elements from which we may learn, not on failings. It concentrates on work which has had little influence upon subsequent thought. I find need for more investigation of economic sub-systems and of the mechanisms that operate over very long periods - centuries and more.