This does not really explain the demographic surge. More mothers had to survive childbirth, with more of their children surviving, in cities that had a long history of being demographic sinks. Was there some shift in midwifery, or in the application of the law, that made childbirth safer? Increased wages seem weak as an explanation, if calories per head did not rise. More urban work opportunities, with calories per head roughly keeping pace, plus reduced maternal and child mortality noted in your previous post would do it.
On the census and poetry (talking people into counting people was curiously difficult) https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/37577/ELN%20pages%2048.2%20Robbins.pdf
This does not really explain the demographic surge. More mothers had to survive childbirth, with more of their children surviving, in cities that had a long history of being demographic sinks. Was there some shift in midwifery, or in the application of the law, that made childbirth safer? Increased wages seem weak as an explanation, if calories per head did not rise. More urban work opportunities, with calories per head roughly keeping pace, plus reduced maternal and child mortality noted in your previous post would do it.