I find that the causal effect of subjective growth expectations on asset prices is far smaller than standard models suggest. To quantify this causal effect, I construct an asset demand model in which Bayesian investors learn from analysts and other signals. A 1% rise in annual investor growth expectations raises price by 60% to 90% less than in standard models. This small causal effect arises from the limited passthrough of beliefs to asset demand, and is consistent with small price elasticities of demand. To reconcile this small causal effect with the strong correlation of growth expectations and prices, I provide evidence of reverse causality. Using flow-induced trading to instrument for prices, I find that prices cause growth expectations.