In economically advanced countries the shape and the size of higher education systems vary substantially. In some countries, access becomes almost universal whereas in others, only about one third in the corresponding age groups enrol. All higher education systems are diversified, but formal dimensions, such as types of institutions or levels of study programmes and degrees play different roles and informal dimensions are by no means irrelevant. In some countries, the hierarchy according to quality and reputation is steep and in others relatively flat. Profiles of individual institutions and programmes might be striking or superficial. This book, based on more than three decades of research, aims to show actual trends in the development of higher education systems. It describes the policy debates in an broad range of countries. Moreover, it provides an overview of varying concepts aiming to explain the dynamics of structural developments. The author shows that comparative perspectives and the search for an internationally "best" or "most modern" solutions at times lead to convergent trends. However, specific policy options dominating and specific traditions of higher education tend to reinforce an international variety of patterns of higher education systems. This book invites readers - policy makers and practitioners in the area of higher education as well as scholars and graduate students - to look beyond the idiosyncrasies of national debates and beyond the "Zeitgeist" of currently fashionable international debates (e.g. Bologna process", "ranking" of "world class universities") and to consider both persistent tensions and changing conditions underlying the extent and the kind of "diversity" opted for on individual countries.