This book explains information agglomeration, a new concept we devise under the influence of Hidalgo (2015). Our concept of information agglomeration applies to an economy with horizontal divisions, while an ordinary concept of industry agglomeration means spillover effects of corporate firms on another ones in vertically integrated industries. In a horizontally divided economy of ‘a society in which the capacities of individuals greatly surpass their individual knowledge’ as Hidalgo (2015) envisages, ‘the combinatorial creativity emerges from our species’ ability to crystallize...