A natural experiment in which customer-owned mutual companies converted to publicly listed firms created a plausibly exogenous shock to the stock market participation status of tens of thousands of people. We find the shock changed the way people vote in the affected areas, with a 10% increase in share-ownership rate being followed by a 1.3%–3.1% increase in right-of-center vote share. The institutional details and additional tests suggest that wealth, liquidity, and tax-related incentives cannot fully explain the results. A plausible explanation is that the associated increase in the salience of stock ownership causes a shift in voters’ attention
