THE old issue of whether population growth is necessary for useful economic growth is now being reconsidered because of a recent U.S. Census Bureau publication predicting reduced fertility. The current “best guess” is that the fertility level of women in the United States has fallen during the past few years to the point where it is now at a replacement rate of 2.1 children per woman during her child-bearing life (ages 14 through 49). Many demographers were estimating only a few years ago that declining fertility would not fall to this replacement level until the 1990’s. Because of net immigration, a replacement level fertility of 2.1 children does not mean that Zero Population Growth (ZPG) is anticipated by this projection. But fertility does seem to be declining, and this has predictable economic and social consequences, more of them good than bad.