popular American writer on science and economics who, as chairman of the National Revenue Commission, helped to create the U.S. Bureau of Statistics and to establish an empirical basis for taxation in the United States.

A graduate of Williams College (1847), Wells later studied under Louis Agassiz (Agassiz, Louis) at the Lawrence Scientific School in Cambridge, Massachusetts. From 1850 through 1866 he and George Bliss published The Annual of Scientific Discovery.

Wells's essay on the national debt, Our Burden and Our Strength (1864), helped restore confidence in the ability of the United States to pay off its Civil War debt. This work, his first on economics, prompted his appointment in 1865 as the chairman of the National Revenue Commission.

In opposition to the Populists in the post-Civil War period, Wells was a strong opponent of fiat money, greenbacks (Greenback movement), and free silver (Free Silver Movement). Throughout his career he defended the doctrines of free trade and laissez-faire, and he emphasized the need for ongoing technological development. Wells also believed that economic crises were usually caused by overproduction.

Wells's most important economic works include Reports of the Special Commissioner of the Revenue (1866–69), which contains an analysis of indirect taxation, Recent Economic Changes (1889), and the posthumous Theory and Practice of Taxation (1900). The last two demonstrate his ability as an empirical investigator. Wells was also one of the highest-paid economists of his era. He earned $10,000 annually (20 times the average annual family income of the time) as a member of the Board of Arbitrators, a private board that heard disputes between railroad firms servicing an area from Chicago to the Eastern seaboard.