Hypocrisy in a Simple Social Interaction Model
(with Mikhail Anufriev and Kirill Borissov), CESifo Working Paper No. 12700, 2026.

Abstract: We develop a model of social interaction in which agents hold private beliefs but communicate public statements. We distinguish between two networks: an audience network shaping statements through social pressure, and an influence network governing belief updating. This separation drives a wedge between public statements and underlying beliefs, so that agents may persistently communicate opinions they do not hold. We provide necessary and sufficient network conditions for the emergence of such hypocrisy. The model generates rich patterns of opinion propagation, including the amplification of messages that agents themselves do not believe, and sheds light on phenomena such as propaganda diffusion, the spiral of silence, and political correctness.

Present-Biased Envy and Inequality
(with Kirill Borissov and Ronald Wendner), Graz Economics Papers 2026-01, University of Graz, Department of Economics, 2026.

Abstract: We analyze the effects of envy (relative consumption concerns), drawing on evidence that preferences exhibit present bias. We introduce present-biased envy, whereby naive agents compare their consumption to that of others only in the current period, into a Ramsey model in which agents differ in their initial capital endowments. Unlike permanent envy, present-biased envy generates the Matthew effect (the relatively rich become richer while the relatively poor become poorer) and eventually divides society into two classes. The initially wealthiest agents own the entire capital stock and the debts of others, while all other agents are in the maximum borrowing state.

Earlier version: Present-Biased Envy, Inequality, and Growth

Endogenous Discounting and Economic Dynamics
(with Kirill Borissov, Stefano Bosi, Thai Ha-Huy and Van-Quy Nguyen), CESifo Working Paper No. 12156, 2025.

Abstract: We study a discrete-time optimal growth model with endogenous discounting. The discount factor may depend on both consumption and the capital stock, and intertemporal utility is modeled as a discounted sum of instantaneous utilities, with the sum of discount factors equal to one. We show that this specification preserves the invariance of optimal paths and steady states to affine transformations of the instantaneous utility function, providing a general and flexible framework for analyzing economic dynamics under endogenous time preference. We prove that optimal capital paths are monotonic, and steady states depend on initial conditions. We also show the robustness of poverty traps under endogenous discounting: in several examples, for a set of parameters with positive measure, the optimal path converges to a positive steady state only if the initial capital stock exceeds a critical level and otherwise converges to the origin.