arXiv subjects

Roberto Serrano

Publications and source records attributed to Roberto Serrano.

3 recordsLinked to original sources

arXiv2026

Comparative Statics of Information Acquisition and Risk Aversion

We study how willingness to pay for information depends on risk aversion when a decision maker faces background risk and can acquire information before choosing from a menu of assets. We distinguish investment menus, whose payoffs are procyclical with background wealth, from insurance menus, whose payoffs are countercyclical. Our main results show that the interaction between asset cyclicality and the tail geometry of background risk determines the direction of the comparative statics. When the density of background risk is log-concave, willingness to pay for information decreases with risk aversion for investment menus, whereas with downward-log-convex background risk it increases with risk aversion for insurance menus. The proofs compare the distributions of terminal wealth with and without information and develop new aggregation arguments for state-dependent single-crossing comparisons. We also construct reversals under strictly log-convex tails for investment menus and super-exponential left tails for insurance menus.

econ.TH↗

arXiv2026

A Rationalization of the Weak Axiom of Revealed Preference

Given a finite collection of choices over budgets, rational consumer behavior is identified with the generalized axiom of revealed preference (GARP). As an alternative, the weak generalized axiom of revealed preference--WGARP--only rules out strict choice cycles of size two. While GARP failures are routinely found in both the field and the lab, the same is not true for WGARP. We study how WGARP-consistent choices can be rationalized as a form of optimal behavior. Our main result is an analogue of the celebrated Afriat's theorem, but for WGARP. We show that choices are consistent with WGARP if and only if they can be rationalized by an asymmetric and strictly monotonic preference function. Equivalently, they can be rationalized by a preference function that admits a coalitional multi-utility (CMU) representation with a coherence restriction. A coherent CMU representation aggregates multiple utility functions --selves-- within the individual, so that binary preference reversals do not occur, while longer preference cycles remain possible. As a result, the class of incomplete, intransitive, and nonconvex preferences compatible with WGARP is studied.

econ.TH↗

arXiv2019

The evolution of kicked stellar-mass black holes in star cluster environments II. Rotating star clusters

In this paper, we continue our study on the evolution of black holes (BHs) that receive velocity kicks at the origin of their host star cluster potential. We now focus on BHs in rotating clusters that receive a range of kick velocities in different directions with respect to the rotation axis. We perform N-body simulations to calculate the trajectories of the kicked BHs and develop an analytic framework to study their motion as a function of the host cluster and the kick itself. Our simulations indicate that for a BH that is kicked outside of the cluster's core, as its orbit decays in a rotating cluster the BH will quickly gain angular momentum as it interacts with stars with high rotational frequencies. Once the BH decays to the point where its orbital frequency equals that of local stars, its orbit will be circular and dynamical friction becomes ineffective since local stars will have low relative velocities. After circularization, the BH's orbit decays on a longer timescale than if the host cluster was not rotating. Hence BHs in rotating clusters will have longer orbital decay times. The timescale for orbit circularization depends strongly on the cluster's rotation rate and the initial kick velocity, with kicked BHs in slowly rotating clusters being able to decay into the core before circularization occurs. The implication of the circularization phase is that the probability of a BH undergoing a tidal capture event increases, possibly aiding in the formation of binaries and high-mass BHs.

astro-ph.GA↗