Abstract
We apply a novel text-based classification method to identify green trademarks in the USPTO dataset and analyze their evolution in the U.S. economy over the past forty years. Because U.S. trademarks require "use in commerce" for registration, our data uniquely capture the commercialization of green innovation, providing insights into firms' commitment to environmental protection and sustainability. Our analysis first shows that the manufacturing, energy, and services sectors lead in the development of green products in the U.S. We then find that firms with a greater number of green products tend to have higher environmental ratings and lower greenhouse gas emissions. Importantly, these firms also exhibit higher firm value-an effect that is statistically significant only among firms with broader product market scope or those facing less intense competitive pressure. Using detailed textual data from trademark registration forms, we further show that green products enhance firm value only when they fall within a firm's core product lines, are not greenfield introductions, or are launched alongside non-green products. Finally, we provide causal evidence that firms increase green product development in response to natural disasters in nearby counties or environmental scandals involving peer firms. To our knowledge, this is the first study to examine whether and how green products contribute to firm value. Our findings highlight an important but underexplored dimension of corporate commitment to environmental protection and sustainability.