This paper presents a series of event studies that measure the stock market
reaction to news about the minimum wage. We use two samples of firms: a broad
sample of companies in low-wage industries; and a narrow sample of firms that
mentioned the cost effects of the federal minimum wage in their recent annual
reports. Our analysis of legislative events leading up to the 1989 amendments
to the Fair Labor Standards Act shows little systematic effect on the market
value of low-wage companies. We also analyze a series of events associated with
a confidential memo from the Secretary of Labor that was leaked in mid-1993.
Here, the stock market reactions suggest that news of a possible change in the
minimum wage may have a modest effect on value of low-wage companies.

We estimate the effect of new unionization on firms’ equity value over the 1961-1999 period using a newly
assembled sample of National Labor Relations Board (NLRB) representation elections matched to stock market
data. Event-study estimates show an average union effect on the equity value of the firm eq uivalent to a cost of at
least $40,500 per unionized worker. At the same time, point estimates from a regression-discontinuity design –
comparing the stock market impact of close union election wins to close losses – are considerably smaller and close
to zero. We find a negative relationship between the cumulative abnormal returns and the vote share in support of
the union, allowing us to reconcile these seemingly contradictory findings. Using the magnitudes from the analysis,
we calibrate a structural “median voter” model of endogenous union determination in order to conduct
counterfactual policy simulations of policies that would marginally increase the ease of unionization.