Uncertainty and Fake News: An Experimental Study on the Strategic Use of Fake News in Belief Formation

This paper investigates the strategic role of low-informative signals – conceptualized as fake news – in shaping belief formation and influencing decision-making under uncertainty. Build ing on the experimental frameworks of Exley (2016) and Garcia et al. (2020), we introduce a novel design that mimics real-world misinformation through signals that are true but partial, fostering biased beliefs. Specifically, we test whether such signals influence individuals to fa vor self-serving options, particularly when the misleading information aligns with their self interest. Our results show strong evidence of excuse-driven behavior under risk-for-self, which is exacerbated by low-informative signals. Notably, the bias induced by weak signals diminishes when outcomes primarily benefit others, highlighting the strategic alignment of be lief distortion with self-interest. These findings underscore the broader philosophical and em pirical importance of understanding how partial information influences motivated reasoning and decision-making, contributing to the literature on misinformation, motivated beliefs, and behavioral economics.