We reformulate Grandmont's and its successors' notion of behavioral heterogeneity such as to get the exact insensitivity of the aggregate budget share function with respect to changes in prices and income, instead of a mere approximate insensitivity. We propose a non parametric set-up such that,...

In the development of the general equilibrium theories, Hicks and Allais played an essential role. We are studying here the contributions which were theirs respectively in Value and Capital (1939) and in the Traité d’économie pure (1943). The accent is put on three points: the theory of...

Short lived arbitrage opportunities arise when prices adjust with a lag to new information. They are toxic because they expose dealers to the risk of trading at stale quotes. Hence, theory implies that more frequent toxic arbitrage opportunities and a faster arbitrageurs' response to these...

L'Union européenne (UE) se trouve confrontée à un besoin critique de terres rares, en particulier de produits raffinés essentiels à la production de voitures électriques, de turbines et d'autres applications technologiques. Cependant, le processus de raffinage est non seulement...

Le continent africain devient de plus en plus un champ de bataille dans la course entre les superpuissances pour l'accès aux minéraux essentiels à la « révolution verte », tels que les minéraux des terres rares (REE). Les entreprises chinoises, américaines et russes jouent un rôle...

The African continent is increasingly becoming a battleground in the race between superpowers for access to critical minerals needed for the 'Green Revolution', such as rare earth minerals (REE). Companies from China, the USA and Russia play a major role. In most cases, critical minerals are...

The European Union (EU) finds itself in a critical need for rare earths, particularly the refined products essential for the production of electric cars, turbines, and other technological applications. However, the refining process is not only energy-intensive but also poses significant...

Our earlier papers had extended to asymmetric information some classical existence theorems of general equilibrium theory, under the standard assumption that agents had perfect foresights, that is, they knew at the outset which price would prevail tomorrow on each spot market. Yet, observation...