Paul Romer, a Nobel prizewinner in economics, said that the procedure appeared to be ‘not justice but politics by other means.’ One member of the tribunal voted against the decision.

In particular, he has been associated with a revival of the use of differential calculus (in the form of "global analysis") at the highest levels of mathematical economics.

[6] Mas-Colell's book "offers a synthetic and thorough account of a major recent development in general equilibrium analysis, namely, the largely successful reconstruction of the theory using modern ideas of differential topology", according to its back cover.

[15] Recently researchers have studied nonlinear pricing: A "main motivation came from the fact that Mas-Colell's fundamental theory of welfare economics with no interiority assumptions crucially requires lattice properties of commodity spaces, even in finite-dimensional settings.

"[16] Mas-Colell is the author or co-author of: Mas-Colell is a foreign associate of the United States National Academy of Sciences, a foreign honorary member of the American Economic Association, a fellow of the American Academy of Arts and Sciences, a member of the Academia Europaea, a member of the Institute of Catalan Studies, a fellow of the Real Academia de Ciencias Morales y Políticas, and a fellow of the Econometric Society.

[18] He is a recipient of the Creu de Sant Jordi, the highest civil honor of Catalonia, and of the King Juan Carlos Prize in Economics.

[2][3][4][5] Also he has received the 2009 BBVA Foundation Frontiers of Knowledge Award in Economy, Finance and Management (co-winner with Hugo F. Sonnenschein).