These are two questions which suggest very different answers:) especially in hindsight:) without specifying where the person lives, my only guess is for the second question—exterminate rats; but it might have been simply impossible to arrive at in 1400, so—lessen taxes?
The impact of tax policy in Malthusian eras is hard to determine—it might adjust the population size, but probably not per capita income. But it does seem like one could convince someone that urbanization is important, and they should focus on solving the city-level problems of sanitation, trade, and economics, which were approached only haphazardly at the time. Convincing them to move to an Imperial Free City and spend their efforts sanitizing it / developing institutions that keep it clean might be useful.
These are two questions which suggest very different answers:) especially in hindsight:) without specifying where the person lives, my only guess is for the second question—exterminate rats; but it might have been simply impossible to arrive at in 1400, so—lessen taxes?
The impact of tax policy in Malthusian eras is hard to determine—it might adjust the population size, but probably not per capita income. But it does seem like one could convince someone that urbanization is important, and they should focus on solving the city-level problems of sanitation, trade, and economics, which were approached only haphazardly at the time. Convincing them to move to an Imperial Free City and spend their efforts sanitizing it / developing institutions that keep it clean might be useful.
That’s part of the point.
Is that possible with XV-century technology and level of social organization?
I think so (based on fictional evidence of a Kipling’s story). For example, the church could damn rats, it would make people united in their efforts.
If we’re going for fictional evidence, it’s easier to train an army of Pied Pipers :-)