As far as I understand command economies, it's not like the government is forcing people to invest their money, it's more like the government decides how much to allocate for consumption and pays it out as salaries -- and the rest it wastes... err, I mean uses for capital spending. In this case the "national saving rate" does not reflect any population preferences, only Politbureau considerations.

Agreed; I think the grandparent refers to money earned by people and spent by the Politbureau as "their" (i.e. the people's) money, which is an implicitly political use of language (because I'm libertarian).

I would also be quite wary of savings statistics coming from communist times as I would expect most savings of actual people to live in shadow/underground economy and not be seen officially.

Agreed.