No sex in the city: All over the developed world, people are having sex less frequently, for reasons largely unknown. http://journals.sagepub.com/doi/abs/10.1177/1363460718785108?journalCode=sexa …pic.twitter.com/5Tu8OXWg9j
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In general terms, a retreat to digital media has indeed been cited as possible cause, but it is just post hoc speculation. My best guess is demographics, fewer young women because of fewer births.