[codekansas]

Per what measure? Are you counting the United States and Western Europe as the #1 economy collectively?

[sudosysgen]

Using either GNP or GDP, the USSR was the State with the second biggest economy for most of its existence.

[frank2]

Sure, if you believe the figures published by the USSR's government.

[newen]

With around the same population as the US too.

[sudosysgen]

Indeed, it was only very slightly more populous than the US.