“Cornucopia: The Pace of Economic Growth in the 20th Century”, 2000-03-01 (; similar):
There is one central fact about the economic history of the 20th century: above all, the century just past has been the century of increasing material wealth and economic productivity.
No previous era and no previous economy has seen material wealth and productive potential grow at such a pace. The bulk of America’s population today achieves standards of material comfort and capabilities that were beyond the reach of even the richest of previous centuries. Even lower middle-class households in relatively poor countries have today material standards of living that would make them, in many respects, the envy of the powerful and lordly of past centuries.