Let A be a. matrix of m rows and n columns and let the entries of A be the integers 0 and 1. We call such a matrix a (0, 1) -matrix of size m by n. The 2 (0, 1)-matrices of size m by n play a fundamental role in a wide variety of combinatorial investigations. One of the chief reasons for this is the following. Let X be a set of n elements Xi, X2, • • • , xn and let Xi, X2, • • • , Xm be m subse...

In the last two decades institutional economics of development has been enriched by historical and, more recently, quantitative analysis of the effects of the quality of institutions on the pace and pattern of economic development. Following the leadership of Douglass North, this literature has shown how important secure property rights are in encouraging investment and innovations, allowing fo...