I don't mind ideas such as "natural size" but it has to mean something based on real things. Real things have changed so fast over the last 150 years that "natural" no longer means something to do with nature. Human brain power has pretty much taken over the whole planet and is now roaming around on Moon and Mars while umpty thousand satellites orbit Earth with a few fired off into the great beyond.
Maybe in human terms there is some "natural" but it's so variable as to be hopeless to determine. For example Aotearoa-Zimbabwe was once number 3 in GDP per person but has now faded to way down the list while countries that were poor when I was a youngster at number 3 have now soared wayyyyy beyond NZ. For example Singapore, Hong Kong, South Korea, Japan. Others such as Hungary, Bulgaria, Poland, East Germany, Spain, have done very well though not so impressive.
The variations are self-selected. Look at China = fantastic improvement in just a single generation, as I said could happen way back in 1986 after the black and white cats were turned loose.
Tiny little England created the Great and Glorious British Empire that brought civilisation to the benighted barbarians and cannibals around the world. They educated people like Mugabe, Idi Amin, Gandhi, Lee Kwan Yew, Eugene Chen and hordes of others. Not all of them adopted VVVs unfortunately, and all too many decided Karl Marx was a splendid chap and adopted the British Disease that Margaret Thatcher tried to eliminate.
So it's not as though "natural size" was real. England can now barely keep itself going let alone quarter of the world. The "natural size" is somewhere between zero and Global Rule.
I can imagine a little country could invent a federal system based on Tradable Citizenship in which individuals own the state as personal property that they can sell, to which other countries could sign up, creating a 3 billion person "country" with many autonomous "Provinces". I'd be very happy to sign up. Voluntary association of sovereign individuals is a wonderful thing.
Mqurice |