Volume 18, numéro 3, 2026

EN :

This paper reinterprets portfolio selection through two Archimedean mechanical principles— the lever law and center-of-mass computation—formalized as explicit constraints within classical mean-variance and factor-model frameworks. The Archimedean Lever Portfolio (ALP) requires asset-specific torques to be proportional to risk contributions; under standard mean-variance assumptions this yields a closed-form solution structurally identical to the tangency portfolio, but using the volatility-scaled signal σiμi in place of raw expected returns μi—an implicit Bayes-Stein shrinkage that lowers turnover and drawdowns. The Archimedean Center-of-Mass (ACM) portfolio is a minimum-variance allocation whose factor center of mass is aligned with the factor risk premium, yielding a second closedform solution from a low-dimensional linear system. Empirical tests on U.S. ETF equity portfolios show that Archimedean portfolios deliver competitive risk-adjusted returns across multiple estimation windows and data frequencies, with lower turnover and smaller drawdowns than the classical tangency portfolio, though results are subject to the usual caveats of a small-universe backtest.

EN :

This paper develops a theoretical framework for understanding how minimum wage policies may create a “poverty trap” that reduces low-wage workers’ incentives to invest in human capital. While minimum wage increases provide immediate income benefits, beyond a certain threshold they diminish expected returns to education and training, thereby reducing occupational mobility. I formalize this relationship through a utility maximization model incorporating time discounting, opportunity costs, and uncertainty. The framework derives explicit conditions under which an inverted-U relationship emerges between minimum wage levels and human capital investment, including bounded skill premia, education affordability constraints, and wage-dependent present bias. Recent empirical work by Alessandrini and Milla (2024) provides partial support, finding minimum wage increases lead to higher community college enrollment but lower university enrollment, consistent with the model’s predictions. The analysis contributes to minimum wage policy debates by highlighting potential trade-offs between short-term income support and long-term economic mobility, suggesting complementary policies are needed.

EN :

Despite legal protections, discrimination remains widespread in labor markets. This paper studies whether anti-discrimination policies improve welfare when discriminatory practices can shift across margins. I develop a reduced-form search model with endogenous vacancy creation and taste-based disutility, where workers face a wage–job-finding probability trade-off. I analyze two interventions: an Equal Pay Policy constraining wages and a Quota Policy constraining hiring probabilities. Wage and hiring discrimination are jointly determined and can substitute for one another, so policies may achieve formal equality while reducing welfare. Equal Pay can eliminate wage gaps but worsen protected workers’ job-finding probabilities when vacancy creation is insufficiently elastic. A quota can equalize hiring probabilities and indirectly wages, yet pool workers into a lower common allocation. The main implication is that anti-discrimination policies should be evaluated as equilibrium interventions affecting wages, vacancies, and employment probabilities, rather than solely by their effect on the targeted margin.

EN :

China’s provincial income distribution has remained stratified through 1992–2024, with club retention probabilities of 0.933 at the bottom and 0.990 at the top. We estimate a spatial Durbin specification in which local absorptive capacity, measured by scientific-services firm density, moderates how neighbors’ initial income affects provincial growth. Two-way fixed effects attenuate this moderation toward zero on the 2011–2019 panel, while instrumenting with 1992–1995 baseline tech density recovers a coefficient of 0.048. Spillovers shift from backwash to spread at a standardized tech density near 0.23, a levelmost provinces remain below. The full 1992–2019 panel yields negative moderation, placing spread effects in the 2010s rather than in the reform era as a whole.