In this paper I shall try to trace associations between certain demographic, educational, economic and social variables and to examine the form of these associations. The method I shall use is a cross-section analysis of country data which, despite differences in definitions and in reliability, has the merit of enabling a wide range of variation to be studied. My first effort in this direction was set out in a paper (1972) in which I made exclusive use of log-linear relationships. Clearly this form could only be approximate since most of the relationships with which I am concerned must, in principle, be sigmoid: for instance, the proportion of the population under 15 or illiterate must lie between 0 and 1. Accordingly, in this paper, besides repeating and extending the results of (1972), I have experimented with several other forms of relationship and displayed the results in a series of diagrams.