I don’t to speak for him, but he may be saying that socialism works better in places where there are less people in theory. This might be because people are less likely to freeload if communities are smaller, and the current capital (before the socialist turn) won’t run out as quickly as it would in densely-populated countries.
Here’s a link to a Mises thread about The Myth of Scandinavian Socialism that krazy kaju started about two years ago.