Campbell is recognized internationally as an authority on Soviet-type economics and technology development in Russia.
He was a Fulbright-Hays Lecturer in Tokyo, Japan, and Bucharest, Romania; and a research visitor at the Soviet Science Policy Research Institute in the Soviet Union. He lectured at Warsaw University and at the Foreign Trade Research Institute in Warsaw, Poland.
Campbell was a consultant for SRI International; the RAND Corporation; Plan Econ; The U.S. State Department; National Science Foundation; the Hudson Institute; Eurasia Foundation; The Open Society Institute; and Barents LLC.
He served in Uzbekistan in 1994 as Senior Economic Advisor to the Government of Uzbekistan, and in 1996-97 organized and served as the resident Program Director of an economics MA program at the University of Kiev-Mohyla Academy in Ukraine (http://www.eerc.kiev.ua). He was chairman of the program's International Advisory Board. In 2005, he received the John W. Ryan Award for contribution to IU's International Programs and Studies.
Campbell held office including the presidency of the American Association for the Advancement of Slavic Studies; chairman, AAASS committee on the Current Digest; president of the Association for Comparative Economic Studies; a member of the editorial board of Slavic Review and a trustee for National Council for Eurasian and East European Research. He wrote numerous books, monographs, and articles.
He received research grants and fellowships from the Ford Foundation; American Council of Learned Societies; National Aeronautics and Space Administration; National Science Foundation; Kennan Institute for Advanced Russian Studies Grants; Harvard University Research Center and IREX.