In this book I have relied on many different forms of empirical evidence, from quantitative to qualitative. I have used two types of quantitative data: time-series and cross-sectional. Most cross-sectional data came from surveys of workers, union representatives, employers, and firms. Some quantitative data came from content analysis of text sources (e.g. newspapers). Qualitative data came from newspapers, case studies, workers' diaries, oral histories, interviews with workers, union leaders, and employers. I list here at least the main sources in the firm belief that they all provide empirical evidence. More generally, however, I have to admit that I ransacked the library shelves, extensively using books and articles as empirical evidence.