INFORMATION ACQUIRED FROM SIX SUPPLEMENTS TO THE REGULAR "CURRENT POPULATION SURVEY" BETWEEN JUNE 1964 AND JUNE 1966 WAS USED TO EXAMINE THE REASONS UNEMPLOYED MEMBERS OF THE LABOR FORCE BEGIN TO LOOK FOR WORK. THE DATA, WHEN AVERAGED, REVEALED THAT DURING THIS PERIOD OF RAPID ECONOMIC EXPANSION (1) 40 PERCENT HAD LOST THEIR PREVIOUS JOBS, (2) 15 PERCENT HAD QUIT THEIR LAST JOBS, (3) 25 PERCENT WERE REENTERING THE LABOR FORCE AFTER A PERIOD OF ABSENCE, AND (4) 20 PERCENT WERE NEW ENTRANTS WHO HAD NEVER HELD A FULL-TIME JOB. IN JUNE 1966, JOB LOSERS, THOSE WHOSE EMPLOYMENT WAS TERMINATED OR THOSE ON LAYOFF, ACCOUNTED FOR ONE-FOURTH OF ALL UNEMPLOYED PERSONS, AND IN DECEMBER 1964 AND JANUARY 1966 THE PROPORTION HAD RISEN TO ONE-HALF. THE NEGRO JOB-LOSER RATE WAS ABOUT TWO AND ONE-HALF TIMES THE WHITE RATE. PERSONS WHO LEFT THEIR JOBS VOLUNTARILY AND IMMEDIATELY BEGAN TO LOOK FOR WORK ACCOUNTED FOR 12 TO 18 PERCENT OF THE UNEMPLOYED. THE DATA SUGGEST THAT THE NEW ENTRANT RATE DURING PERIODS OF ABUNDANT JOB OPPORTUNITIES MAY KEEP UNEMPLOYMENT RATES UP. SINCE OVERALL ECONOMIC EXPANSION SEEMS TO AFFECT ENTRANT AND JOB-LEAVER RATES VERY LITTLE AND VERY SLOWLY, JOB MARKET PROGRAMS AIMED AT SPECIFIC GROUPS WILL BE NEEDED TO REDUCE THE TOTAL UNEMPLOYMENT RATE BELOW THREE AND ONE-HALF PERCENT. THIS DOCUMENT APPEARED IN THE "MONTHLY LABOR REVIEW," JANUARY 1967. (ET)