I love the Socialist country pool they took from. USSR, Poland, Czechoslovakia, East Germany, Yugoslavia, Hungary, Romania, Bulgaria, China, Cuba, Mongolia, North Korea, Albania.
Most of these places abandoned Socialism today (note the study was taken 30 years ago). China took in corporatism, Mongolia abandoned Socialism in '92, Yugoslavia failed, Romania’s Socialist president was executed for crimes against Yugoslavia, Poland went through the Balcerowicz Plan, North Korea has to build walls to keep people in, Bulgaria’s Socialist government failed and was replaced, East Germany morphed with West Germany, Albania stopped being Socialist in '92 (they did elect the Socialist party in 2013 though) and Cuba is the most successful Socialist country on the planet.
It’s almost as if most Socialist countries fail because collectivization, high tax, and limited freedoms are not very good compared to private ownership, low tax, and nearly total freedom; who would have thought.