[23] In 2023, he returned to France, joined the Paris School of Economics, and remains a Senior Fellow of the Peterson Institute.

[24] Olivier has mentored a number of notable students throughout his academic career, including David Laibson, Tobias Adrian, Laurence M. Ball, Roland Bénabou, Ricardo J. Caballero, and Pierre-Olivier Gourinchas, among many others.

[29] The identification of demand and supply shocks, with Danny Quah, through long-run restrictions in a VAR representation.

[30] The “divine coincidence” result, derived in research with Jordi Gali, that, in the baseline New Keynesian model, stabilizing inflation, which is good on its own, also leads output to be equal to its constrained optimum; this baseline result allows to think about the nature of the trade-off that emerges between inflation and output when other distortions are introduced.

The effect of real wage rigidities on fluctuations and the role of monetary policy, with Jordi Gali.

[35] Blanchard explored the “hysteresis” hypothesis, namely that transitory shocks may have a permanent effect on participation or unemployment, with Lawrence Summers.

[36] The channels through which this may happen include union wage setting with insiders and outsiders, and loss of skills or morale when unemployment is high.

He additionally examined gross flows in labor markets, and the determination of equilibrium unemployment and vacancies, with Peter Diamond.

[40] The set of optimal labor market institutions, from unemployment insurance to severance payments, with Jean Tirole.

In the early 1990s, Blanchard became involved in transition from central planning to a market economy in Eastern Europe.

In a book based on a series of lectures,[43] he discussed how to think about the various privatization options, and about the speed of transition.

In an article with Michael Kremer, he argued that the large decrease in output at the start of the transition, despite the shift to a set of market prices, was due to “disorganization”, the failure of supply chains; the mechanism became relevant again in the face of supply chain disruptions during the covid and energy crisis inflation of the early 2020s.

MIT Press published those conclusions in a series of books, containing short articles by a wide set of important economists, and summaries by Blanchard and different co-editors.

With the support, first of Dominique Strauss Kahn, then of Christine Lagarde, he was given wide range to think about the issues raised by the two crises, and influence the position of the Fund on issues such as unconventional monetary policy, macro prudential policy, fiscal austerity, the pros and cons of capital flows, the effect of the crisis on emerging market countries.

In particular, he argued that short horizon capital flows were often costly, both when they came in and overwhelmed the domestic financial system, and when they suddenly went out.

[58] Under Blanchard's tenure at IMF, Jonathan D. Ostry and Andy Berg published their findings that "inequality was detrimental to sustained growth.

"[59][60] By April 2014, in the World Economic Outlook, Blanchard situated inequality as a "central issue" for "macroeconomic developments and one that the IMF should take into account".