Short answers, pulled from the story.
Olivier Blanchard is a French economist born on the 27th of December 1948 in Amiens, France. He is Robert M. Solow Professor Emeritus of Economics at MIT, a leading figure in New Keynesian economics, and former chief economist of the International Monetary Fund, where he served from 2008 to 2015.
Blanchard served as Economic Counsellor and Head of the Research Department at the IMF from September 2008 to 2015. He supported global fiscal stimulus during the Great Recession, challenged the Fund's approach to fiscal austerity, and helped shift IMF policy on capital controls and inequality.
In 2012, Olivier Blanchard and Daniel Leigh found that countries pursuing stronger fiscal consolidation also tended to underperform their own output forecasts. They concluded that the adverse effects of fiscal austerity, the so-called multipliers, were larger than the IMF and EU Commission had assumed, prompting a reassessment of IMF advice.
The divine coincidence is a result derived by Blanchard and Jordi Gali showing that in the baseline New Keynesian model, stabilizing inflation simultaneously pushes output to its constrained optimum. The result helps economists identify the conditions under which a real trade-off between inflation and output actually exists.
Blanchard co-authored Lectures on Macroeconomics with Stanley Fischer in 1989, which became a widely used graduate text. He also wrote an undergraduate textbook called Macroeconomics, first published in 1997; the ninth edition appeared in 2024 and the book has been adapted into 21 foreign editions.
Blanchard's doctoral students at MIT include Jordi Gali, David Laibson, Tobias Adrian, Laurence M. Ball, Roland Benabou, Ricardo J. Caballero, and Pierre-Olivier Gourinchas. Gourinchas later became chief economist of the IMF, the same role Blanchard himself held.