Recent years have not only witnessed a spectacular proliferation of preferential trade agreements (PTAs) but also a surprising growth in the references to labor rights in those. This is a remarkable development given the failed attempt to include a social clause to trade at the multilateral level in the 1990s. We still know fairly little about the causes and consequences of labor provisions in PTAs. The project is primarily interested in the domestic determinants of variation in the design of labor provisions in PTAs, and in the social and economic impact of the inclusion of such provisions in trade agreements. Being the first of its kind, the project sets as its main goal to fill this gap and thus to systematically investigate the above questions, primarily through a set of quantitative studies complemented by a number of qualitative case studies to examine outliers identified based on basic parameters. The key outputs of the project includes the construction of an original dataset on the content of labor provisions in PTAs (LABPTA) and four core articles, two assessing the origins and two assessing the effects of labor provisions in PTAs. According to our main findings: 1) labor provisions do not amount to “protectionism in disguise” as exports from low income countries benefit from the introduction of labor provisions in North-South trade agreements; 2) soft, cooperation- related labor provisions can be effective in improving state compliance with collective labor rights; and 3) the role of trade unions is vital both in the design and the implementation of labor provisions.