Patterns in the press releases of trade unions : how to use structural topic models in the field of industrial relations

Quantitative text analysis and the use of large data sets have received only limited attention in the field of Industrial Relations. This is unfortunate, given the variety of opportunities and possibilities these methods can address. We demonstrate the use of one promising technique of quantitative text analysis - the Structural Topic Model (STM) - to test the Insider-Outsider theory. This technique allowed us to find underlying topics in a text corpus of nearly 2,000 German trade union press releases (from 2000 to 2014). We provide a step-by- step overview of how to use STM since we see this method as useful to the future of research in the field of Industrial Relations. Until now the methodological publications regarding STM mostly focus on the mathematics of the method and provide only a minimal discussion of their implementation. Instead, we provide a practical application of STM and apply this method to one of the most prominent theories in the field of Industrial Relations. Contrary to the original Insider-Outsider arguments, but in line with the current state of research, we show that unions do in fact use topics within their press releases which are relevant for both Insider and Outsider groups.