arXiv subjects

Stefano Bosi

Publications and source records attributed to Stefano Bosi.

3 recordsLinked to original sources

arXiv2026

To Bubble or Not to Bubble: Asset Price Dynamics and Optimality in OLG Economies

We study an overlapping generations (OLG) exchange economy with an asset that yields dividends. First, we derive general conditions, based on exogenous parameters, that give rise to three distinct scenarios: (1) only bubbleless equilibria exist, (2) a bubbleless equilibrium coexists with a continuum of bubbly equilibria, and (3) all equilibria are bubbly. Under stationary endowments and standard assumptions, we provide a complete characterization of the equilibrium set and the associated asset price dynamics. In this setting, a bubbly equilibrium exists if and only if the interest rate in the economy without the asset is strictly lower than the population growth rate and the sum of per capita dividends is finite. Second, we establish necessary and sufficient conditions for Pareto optimality. Finally, we investigate the relationship between asset price behaviors and the optimality of equilibria.

q-fin.CP↗

arXiv2026

A note on first-order and transversality conditions in infinite-horizon continuous-time optimal control models

We provide simple and easily verifiable necessary and sufficient conditions for infinite-horizon continuous-time optimal control problems. Under standard concavity and integrability assumptions, we show that optimal paths are fully characterized by first-order conditions together with a transversality condition. Importantly, the transversality condition is derived as a consequence of the model's structure rather than imposed a priori. Our results apply directly to standard economic models, including optimal growth and consumption--saving problems.

math.OC↗

arXiv2026

AI Contagion in Social Networks

We study how artificial intelligence (AI) interacts with social communication networks to shape the stability of collective knowledge. Agents exchange information through a network while AI systems generate content and retrain on the aggregate informational environment they influence. This interaction creates a recursive feedback loop in which informational distortions diffuse through society and subsequently feed back into future AI outputs. Despite the high dimensionality of the environment, we show that the long-run dynamics admit a two-dimensional representation whose spectral radius completely characterizes the stability of AI-mediated information systems. We derive a sharp regulatory frontier identifying the minimum filtering required for stability and show how homophily and core-periphery network structures shape systemic informational risk.

econ.TH↗