On a national scale, private retirement savings are not that different from pensions. Both are based on tokens that entitle you to some fraction of the economic output of those who do productive work. The value of a token depends on the total number of tokens, the size of the real economy, and the fraction of value the people doing productive work are willing to pay as taxes to the government and the capitalists.
Investing internationally changes some things. Retirees bring in money from abroad, but that does not increase domestic production. Prices will go up, as there is more money competing for the same goods and services. The people doing productive work will want more money for their services. Imports will be relatively cheaper, but the economy suffers, because the exports will be less competitive due to higher wages.
Saving for retirement is rational for any individual if the demographic structure cannot support the pension system. But while anyone can do it successfully, it's not possible for everyone at the same time.
Investing internationally changes some things. Retirees bring in money from abroad, but that does not increase domestic production. Prices will go up, as there is more money competing for the same goods and services. The people doing productive work will want more money for their services. Imports will be relatively cheaper, but the economy suffers, because the exports will be less competitive due to higher wages.
Saving for retirement is rational for any individual if the demographic structure cannot support the pension system. But while anyone can do it successfully, it's not possible for everyone at the same time.