The occurrence of strikes and lock-outs is an important feature of labour relations in industrialized market economies. These two types of concerted activity by industrial workers and civil servants are the direct result of the conflict of interest and ideology that is inherent in industrial relations. This conflict evolves around the questions of power distribution and group autonomy vis--vis the capital owners and the State. While the phenomenon of strikes and lock-outs has existed ever since the beginnings of industrial society, there have been some significant changes in the nature and occurrence of strikes and lock-outs in the past few decades. These changes and new trends that may be detected in today's forms of industrial action is one of the themes discussed in this volume of the Bulletin. To name two: An increased heterogeneity and specialisation within the labour force. The direction of industrial action against the general public, the consumers, rather than against the capital owners and the growing importance of the service sector employees within the working population. Developments such as these have an impact on labour relations and the accompanying conflicts such as strikes and lock-outs, as you will discover reading this new Bulletin.