The son of Andrew and Mary Nowlin Paton, he was born on July 19, 1889, near Calumet, Michigan. His father was then superintendent of the local school system; his mother was also an experienced teacher. In 1897, the family settled on a farm in southern Michigan.
After some delay because of the pressure of farm work, he finally started college study at Michigan State Normal College (now Eastern Michigan University), and in the fall of 1912 he enrolled at the University of Michigan. He pursued a graduate program after graduating with an AB degree, and received the Ph.D. in economics in 1917. He was elected to Phi Beta Kappa in his senior year at Michigan and later became a member of Beta Alpha Psi and Beta Gamma Sigma. During his career he has received a number of honorary degrees, including the Litt. D. (LeHigh University) and the LLD (Eastern Michigan University).
In 1914, he began his long teaching career at the University of Michigan as a part-time instructor. And on the strength of this appointment, so he says, he married Mary K. Sleator, a U of M graduate, then teaching mathematics in the Battle Creek (Mich.) school system. For the school year 1916-17 he served as an assistant professor at the University of Minnesota, and then returned to his alma mater. He was promoted to full professor in 1921, and retired in 1958 with the title "professor emeritus of accounting and of economics."
While on leave from the University of Michigan he taught at the University of California (Berkeley) for the school year 1937-38. Since retiring at Michigan he has done part-time teaching at universities in ten states, beginning with the University of Chicago (1959-60) and ending with University of Kentucky (1968-69).
That his family is addicted to the teaching profession, it should be noted, is further evidenced by the fact that his son and namesake, William A., Jr., also holds the University of Michigan Ph.D. and taught accounting at the university level for more than thirty years, and his daughter Margaret, a Michigan alumnus with a master's degree, was a teacher before her marriage, including several years at Michigan State University.
During the academic year 1939-40 he was the Dickinson Lecturer at Harvard, the first academician to be selected for that honor, and over the years he has served as a special lecturer at a number of universities. He has been in demand as a speaker, and has given many talks to professional associations, business organizations, academic societies, and other groups. He takes pride in never missing a class because of such engagements, though this has meant a lot of night flying.
He helped found what is now the AAA in 1916, and was elected president in 1922. He was largely responsible for the launching of The Accounting Review, in 1926, and served as both editor and production manager the first three years. In 1940 the AAA published An Introduction to Corporate Accounting Standards, prepared by himself and A. C. Littleton. He also served the AICPA in several capacities, notably as a member of the Committee on Accounting Procedure (1939-50). He has long been a member of the Michigan Association of CPAs.
He became a CPA (Michigan) in 1927, but his practical experience in the field of accounting has been largely confined to special consulting engagements during vacation periods. He has frequently appeared as an expert witness before courts, federal and state commissions, arbitration hearings, Congressional committees, and other official bodies. During the academic year 1918-19, he was on leave in Washington, first with the Bureau of Research and Statistics, War Trade Board, and later as Chief of Special Assignments, Income Tax Unit, Bureau of Internal Revenue (old name). He was director of the Kalamazoo Vegetable Parchment Co. and, later KVP Sutherland Paper Co., 1952-63, and was for many years a trustee of Barhart Foundation of the Foundation of Economic Education, Inc. Among many special assignments was his membership on the Education Consultant Committee, U. S. General Accounting Office, 1959-63.
Among the many honors bestowed upon him are the AICPA's Gold Medal Award (1944), Alpha Kappa Psi Foundation Accounting Award (1953), and the Michigan Association of CPAs' first Distinguished Service Award. In 1961 the Michigan Association of CPAs established the William A. Paton Award, which honors the candidate with the highest score on the semi-annual CPA examination (in Michigan). In 1955 the William A. Paton Fund for Accounting Scholarships and Fellowships was established at the University of Michigan. On June 11, 1976, a new building was dedicated at the University of Michigan, named the William A. Pedon Center for Accounting Education and Research. This structure was financed entirely by former students and other friends. In 1987 the AICPA designated him the Outstanding Educator of the Century. This special, one-time award was given at the AICPA's 100th annual meeting in 1987.
He is author or co-author of many books, including his classic Accounting Theory (1922), Principles of Accounting (1918), Corporate Profits as Shown by Audit Reports (1935), Essentials of Accounting (1938), Advanced Accounting (1941), Shirtsleeve Economics: A Commonsense Survey (1952), Corporation Accounts and Statements (1955), Corporate Profits-Measurement, Distribution, Reporting, Taxation (1965), Assets - Accounting and Administration (1971). He was editor of (and a major contributor to) the 1932 and 1943 editions of the Accountants' Handbook. Over a 60-year period, beginning in 1916, he has published more than 150 articles.
He has dabbled in sports, especially track and tennis, tried his hand at flying, and claims that his article entitled "On Going Underground" is still the only systematic account of the advantages of subsurface housing. His love for the English language led to the publication in 1984 of his book, Words! Combining Fun and Learning.
On the Friday (July 14,1989) preceding his 100th birthday in 1989, a party was given at the business school on the University of Michigan campus to celebrate the occasion. More than 200 former students, friends, and colleagues were on hand to share birthday wishes. He died April 26, 1991 at the age of 101.