The book gives an assessment of the following research question: To what extent can the American class action experience help Europeans in building a model of collective redress for mass harm situations? Whether this can be done is not immediately clear since the US class action belongs to the area of private enforcement, whereas Europe prefers public enforcement. The following sub-questions are analysed: (i) How do the United States deal with mass harm situations?; (ii) How do the EU Member States deal with mass harm situations?; (iii) To what extent does the US provide a model for collective redress schemes that fit the European hesitant approach to managerial judging, interdiction of entrepreneurial lawyers, application of the loser pays principle, hesitant approach to contingency fees (pactum de quota litis) and fact pleadings (the common core of European civil proceedings) in the implementation of Directive (EU) 2020/1828?