The linkage between labor standards and trade agreements pursued by the US, and the burgeoning corporate codes of conduct that seek to strengthen core labor standards in global supply chains, has resulted in interest in the development of measures (or indicators) of core labor standards by a variety of organizations, such as the US dept of Labor, the ILO and several NGOs. We argue in this paper that measures of freedom of association and collective bargaining that are in use currently are incomplete and flawed, partly because they focus almost exclusively on whether the rights exist, without regard to practice, and partly because they tend to focus on easily available quantitative indicators that are necessary but insufficient indicators of the freedom of association and collective bargaining process. We develop new measures that draw on decades of comparative industrial relations research and which are based on the existing cross-national variation in industrial relations practice. Our suggested measures require national experts to use both quantitative data and qualitative research and judgment in their evaluation, and report it in consistent and transparent ways. Given that the connection between trade and labor standards makes the consequences of violation quite severe for developing countries, reliance on imperfect measures to make decisions about country performance on core labor standards is problematic. The measures advanced in this paper reduce that risk.