That PhD: can it find a home outside of academia?

Why toil for a PhD?

Most who did it in the past saw it as a necessary ticket to staying in academia - either to teach or conduct research.

Lately, due to the excess of degreed professionals available to colleges and universities, more PhD recipients have been taking their degrees off campus into business and industry. A number of oil companies and banks, for instance, have recently hired new employees with PhD's in history.

''There's a growing interest nationally among those earning PhD's in employment opportunities outside the academic community,'' confirms Michael Pelczar Jr., president of the Council of Graduate Schools in the United States.

That fact, plus the expected graduate-school enrollment drop, particularly in social sciences and humanities, are prompting many graduate schools to rethink the purpose of the PhD and the rigors of its academic requirements.

One idea that appears, in the words of a gradutate student, to be ''coming up strong'' is the mixing of disciplines.

Mr. Pelczar cites the following examples: Claremont (Cal.) Graduate School combines a masters degree in business administration with another masters or PhD in the humanities; the Pennsylvania State University offers a masters degree combining French language and culture with business administration. ''These are by no means to be interpreted as drifting away from the hard-core disciplines,'' he cautions. ''The programs simply have broader options built into them so students with diverse interests can select what appeals - and not be restricted to past patterns.''

Most recently the mixed-discipline idea received a strong boost from a two-year study on the future of graduate education by a University of Chicago faculty commission. The report noted that PhD study should provide, not only training for academic teaching and research, but ''liberal'' education for those thinking of other careers.

The authors suggested, for example, that combining the study of European politics and institutions with the area's languages and literature could prepare better diplomats, journalists, and businessmen, as well as better teachers.

The Chicago research team also suggests that one way to stem the expected decline in candidates for social-science and humanities degrees is, in effect, to tailor the pattern of study after that in the physical and biological sciences. Natural-science graduate students tend to begin independent research early and work in close collaboration with senior scholars. The Chicago report suggests that social-science and humanities students have been deprived on both counts.

The faculty commission recommends filling the gap by calling for only two, instead of three, years of formal PhD course work and having graduate students attend continuous workshops and advanced seminars with top scholars during the dissertation phase. The aim, says the report, would be to reduce any sense of isolation and provide a stronger network of contacts for those studying social sciences and humanities.