Matt Yglesias points out that Arnie didn’t actually live under the Soviet boot, just near it. Which is true, and also what Arnie said in his speech. Matt also goes on to point out that Austria was a social democratic country with a mixed economy:

Then everybody’s troops came home and Austria became a democracy, whose democratically elected governments constructed a mixed economy, much like the democratically elected governments in the United States, Canada, Australia, and the rest of western Europe. As elsewhere in Europe, the Austrian welfare state was more generous than the American one, but as an politico-economic type the two models were very similar — a liberal democratic government, an economy organized along market principles but constrained by regulation in which government programs were financed through taxation.

Most commenters upon the variety of economic structures would put Austria at one extreme of possible social democratic structures: but what Matt says is true enough as far as it goes.
Indeed, one could argue that the Austrian system is close to what people like the EPI argue for in the US….presumably a vision that Matt shares.
So what was so wonderful about that system that Arnie upped and left as soon as he could?