He was for over 30 years and continued to be even after his academic retirement a noted researcher in the area of structural reform of U.S. tax law.
[3] His work is of particular importance in the area of proposals for U.S. federal "Integration" of corporate and individual taxation.
His articles have been translated into several foreign languages, including Korean, Japanese and German.
Notable among these articles are: McNulty has also written 7 textbooks on tax law.
[6][7] McNulty, was, subsequently, a law clerk to U.S. Supreme Court Justice Hugo Black from 1959 to 1960.