{'fraction_non_alphanumeric': 0.016, 'fraction_numerical': 0.0288, 'mean_word_length': 4.961904761904762, '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}}
Birth intervals and women's economic activity

Summary Some hypotheses regarding birth spacing and women's work are outlined. Using British census and survey data it is shown that average second and third birth intervals were shorter in marriages taking place in the 10 years following the Second World War as compared with marriages in the period 1900–29; the intervals increased again, measured on a period basis, in the 1970s. Birth intervals for women married during the 10 years after the war were shorter among those economically active at the 1971 census than among the inactive. Some problems of method are discussed.