3 citations · 5 across the 9 of their papers we have counts for
6 papers · 1 filter
A Rigorous Proof of the Index Theorem for Economists
Yuhki Hosoya
This paper provides a rigorous and gap-free proof of the index theorem used in the theory of regular economy. In the index theorem that is the subject of this paper, the assumption…
Differential Characterization of Quasi-Concave Functions without Twice Differentiability
Yuhki Hosoya
This paper presents a necessary and sufficient condition for a real-valued function defined on an open and convex subset of a Banach space to be quasi-concave, and a sufficient con…
On Gale's Contribution in Revealed Preference Theory
Yuhki Hosoya
We investigate Gale's important paper published in 1960. This paper contains an example of a candidate of the demand function that satisfies the weak axiom of revealed preference a…
On the Fragility of the Basis on the Hamilton-Jacobi-Bellman Equation in Economic Dynamics
Yuhki Hosoya
In this paper, we provide an example of the optimal growth model in which there exist infinitely many solutions to the Hamilton-Jacobi-Bellman equation but the value function does…
Non-Smooth Integrability Theory
Yuhki Hosoya
We study a method for calculating the utility function from a candidate of a demand function that is not differentiable, but is locally Lipschitz. Using this method, we obtain two…
On the Uniqueness and Stability of the Equilibrium Price in Quasi-Linear Economies
Yuhki Hosoya
In this paper, we show that if every consumer in an economy has a quasi-linear utility function, then the normalized equilibrium price is unique, and is locally stable with respect…