This article argues that global labour history (GLH) and global economic history have much to offer each other. GLH would do well to raise sweeping questions – for instance about the origins of global inequality – engage more with theory, and increasingly use quantitative methods. Instead of seeing labour and labour relations as historical phenomena to be explained, they can serve as important explanatory variables in historical analyses of economic development and divergence. In turn, economic historians have much to gain from the recent insights of global labour historians. GLH offers a more inclusive and variable usage of the concept of labour, abandoning, as it does, the often narrow focus on male wage labour in the analyses of many economic historians. Moreover, GLH helps to overcome thinking in binary categories, such as “free” and “unfree” labour. Ultimately, both fields will benefit from engaging in joint debates and theories, and from collaboration in collecting and analysing “big data”.

In our reply to Elise van Nederveen Meerkerk’s “Big Questions and Big Data: The Role of Labour and Labour Relations in Recent Global Economic History”, we focus on her observations on the Global Collaboratory on the History of Labour Relations. We endorse many of her suggestions to connect global labour and economic history and to regard labour relations not only as a dependent variable. In fact, as the examples from various Collab workshops and publications show, some of these ideas are already being put into practice. These examples also show that if we seriously want to combine global labour and economic history data and join the debate on the growth (or decrease) in social inequality, workers’ individual and collective agency must be taken on board. Finally, we argue that global labour and economic historians can benefit most from each other’s disciplines by truly working together in collaborative projects, developing new theories, perhaps less grand than those with which economic historians attract so much attention, but more profound.

Precarious labour has been on the rise globally since the 1970s and 1980s. Changing labour relations in the cleaning industry are an example of these developments. From the 1970s onwards, outsourcing changed the position of industrial cleaners fundamentally: subcontracting companies were able to reduce labour costs by recruiting mainly women and immigrants with a weak position in the labour market. For trade unions, it was hard to find a way to counteract this tendency and to organize these workers until the Justice for Janitors (J4J) campaigns, set up by the US-based Service Employees International Union (SEIU) from the late 1980s, showed that an adequate trade union response was possible. From the mid-2000s, the SEIU launched a strategy to form international coalitions outside the US. It met a favourable response in several countries. In the Netherlands, a campaign modelled on the J4J repertoire proved extraordinarily successful. In this article, transnational trade unionism in the cleaning industry based on the J4J model will be analysed with a special focus on the Dutch case. How were local labour markets and trade union actions related to the transnational connections apparent in the rise of multinational cleaning companies, the immigrant workforce, and the role of the SEIU in promoting international cooperation between unions?