I don't know if the density part is really relevant. One the whole, they are comparable. Country to US it varies, and States (US) to other countries it varies even more [0]. I have lived in several very densely populated cities and they all still do porch drop off. I think this may just fall down to a cultural difference than anything else.

[0] https://www.lesswrong.com/posts/Hifamb4LTgQooDBYj/worth-reme...