In any case, even accepting an argument as retarded as that
There’s no need for language like that. Anyway, for countries where resource wealth (e.g. Russian oil and gas) is a big chunk of the economy, population can indeed have a big effect on per capita wealth (see Kuwait, Saudi Arabia). Likewise, if you have big wealth inequality, e.g. between peasant farmers and urbanites/factory workers, famines among poor farmers can easily raise per capita income.
There’s no need for language like that. Anyway, for countries where resource wealth (e.g. Russian oil and gas) is a big chunk of the economy, population can indeed have a big effect on per capita wealth (see Kuwait, Saudi Arabia). Likewise, if you have big wealth inequality, e.g. between peasant farmers and urbanites/factory workers, famines among poor farmers can easily raise per capita income.