Consumption-Investment with anticipative noise
Abstract
We revisit the classical Merton consumption--investment problem when risky-asset returns are modeled by stochastic differential equations interpreted through a general -integral, interpolating between It\^{o}, Stratonovich, and related conventions. Holding preferences and the investment opportunity set fixed, changing the noise interpretation modifies the effective drift of asset returns in a systematic way. For logarithmic utility and constant volatilities, we derive closed-form optimal policies in a market with risky assets: optimal consumption remains a fixed fraction of wealth, while optimal portfolio weights are shifted according to , where is the return covariance matrix and denotes the diagonal matrix with the same diagonal as . In the single-asset case this reduces to . We then show that genuinely state-dependent effects arise when asset volatility is driven by a stochastic factor correlated with returns. In this setting, the -interpretation generates an additional drift correction proportional to the instantaneous covariation between factor and return noise. As a canonical example, we analyze a Heston stochastic volatility model, where the resulting optimal risky exposure depends inversely on the current variance level.
Keywords
Cite
@article{arxiv.2602.08527,
title = {Consumption-Investment with anticipative noise},
author = {Mario Ayala and Benjamin Vallejo Jiménez},
journal= {arXiv preprint arXiv:2602.08527},
year = {2026}
}
Comments
21 pages