A method of estimating market structure and tax incidence when data are available for some firms and the total industry is applied to the domestic Japanese television market. This market is shown to be oligopolistic with a tax incidence on consumers greater than 100%. Tax incidence varies with both the tax rate and the market structure, which has implications for dumping cases. The size of the bias in estimating tax incidence from inappropriately assuming that the industry is competitive is theoretically derived and the bias for color televisions is 19%.