A union and a firm bargain about wage increases. The firm possesses private information about its revenues. A two-period screening model is used to derive equilibrium wage demands by the union and to calculate measures of strike activity. Changes in wage demands and dispute probabilities due to alterations in various taxes are analysed. A more progressive income tax, a lower level of income taxes and higher payroll taxes reduce wages and strike activity. Hence, tax policy can be used not only to affect wages and employment, but lso to influence strike incidence.