Citing the "tremendous vigor of technology" required by modern civilization, Sumner H. Slichter, Lamont University Professor, predicted Thursday that the capital expansion involved may duplicate by 1990 the increase in reproducible wealth accomplished in the United States during the 60 years prior to World War II.

Professor Slichter made his remarks at a meeting of the finance conference of the American Management Association in the Biltmore Hotel, New York.

Slichter arrived at three tentative estimates of reproducible wealth outside of households in the year 1990, based on the fact that between the years 1879 and 1939, reproducible wealth increased eight-fold in this country.

Three Estimates

$913 billion, $789 billion, and $1,321 billion were the figures submitted by Slichter, based respectively on records of increase per worker and on recent rates of increase in the national income. Somewhere between "the fairly wide range of $800 billion and $1,300 billion is to be found the correct figure for reproducible wealth in the year 1990," Slichter declared.

Stating that technological change will be more rapid than ever before in the next 40 years, Slichter attributed the long-term demand for capital to population growth, technological discoveries, inflationary methods of meeting the need for capital, and government policies.