Assesses the foreseeable need for public assistance to the poor over the next three decades, and ascertains how this need would differ if Americans averaged three or two children per family. Official 1969 federal standards are used for the present poverty line, with two alternative assumptions: the standards will remain constant; and they will increase at the same rate as per capita money income. Results indicate that the aggregate needs of the poor are not very sensitive to different population growth rates. Results also indicate that even with economic growth, the dollar need for public assistance may decline slowly but could actually increase. To eliminate poverty by the year 2000, economic growth probably will require policies redistributing income toward the lowest income classes. Such a redistribution may be easier to afford in the future than now, because the percentage of the gross national product needed for public assistance will almost certainly decline. 48 pp.