Galbraith is one of my all-time favorite authors. It's not only his very elegant prose (before reading Galbraith, I didn't know that books about economics can be fun and even hilarious.) Galbraith, himself a Harvard Professor, is able to explain economic problems and elucidate technical dicussions - perhaps "to teach about economics" would be a more suitable expression - even to non-economists like me.
This is a good book. Three main hypotheses are that power within corporations has shifted from shareholders to management, that the private sector has to a great extent taken control over the public sector, and that it is impossible to foretell financial or economic crises. Nevertheless, in my view this book is not one of Galbraith's finest - but it still is a good book.