Study of jobless ranks

Nearly 1 of every 10 American workers is unemployed, according to the recent 9.8 percent unemployment figure.

A researcher at Johns Hopkins University, Dr. M. Harvey Brenner, conducted an unemployment study based on data from 1940 to 1970. He found that 1 of every 5 Americans was unemployed at some time during 1981. This brought the total to 23. 4 million - 2 million more than the previous year.

Dr. Brenner said the person likely to be most affected by loss of a job is a middle-income, skilled or highly skilled professional - particularly if he is out of work for a long time.

''To the extent that a person is bound up in a self-expressive job that cannot easily be replaced, the impact is profound,'' he said.

Brenner says job seekers start out enthusiastically, but if the search goes on a long time,many are discouraged and find it difficult to approach prospective employers.