{'fraction_non_alphanumeric': 0.036414565826330535, 'fraction_numerical': 0.015406162464985995, 'mean_word_length': 4.458015267175573, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Spatial Diffusion: An Historical Geography of Epidemics in an Island Community. By A. D. Cliff, P. Haggett, J. K. Ord and G. R. Versey. Pp. xi + 238. (Cambridge University Press, 1981.) £19.50.

Some of the ethical problems are extremely complex and hard to resolve. The critical problem remains of balancing inroads into freedom now by the incentives and disincentives of population policy against the possible or even probable inroads into human welfare by the potential over-population and excessive competition for scarce resources of the future. This book contains a great deal of interesting and important material which may be read with profit by all concerned with the population and developmental process.