Richard Erickson, a doctoral candidate at Berkeley, has accepted an offer for an assistant professorship in the Economics Department, Dwight H. Perkins, chairman of the department, said yesterday.

Erickson specializes in econometrics and economic planning, particularly Soviet economic planning. This background is unusual, Roy Radner, Harvard's visiting Taussig Research Professor and Erickson's thesis adviser at Berkeley, said yesterday. Mathematical theory is usually applied to western economies. he added.

Perkins said the department selected Erickson primarily for his background in theory and planning.

He said there is a need for specialists in that area because Truman F. Bewley, associate professor of Economics and an econometrics specialist, is leaving at the end of the year. He added, however, the department did not hire Erickson specifically as a replacement.

First-year assistant professors usually teach sections in Economics 10 and a course in their special field during the spring semester. Perkins said Erickson will probably teach a theory or planning course.

Erickson is now in Moscow on a Fulbright scholarship completing his doctoral thesis.