Final answer:
Postcommunist economic reform has been most successful in Eastern European countries that implemented market-oriented economic reforms and embraced democracy.
Step-by-step explanation:
Postcommunist economic reform has been most successful in the Eastern European countries that have embraced market-oriented economic reforms and transitioned from communism to capitalism. These countries, such as Slovenia, have experienced strong economic growth and have been accepted into the European Union (EU).
During the post-communist transition, Eastern European countries underwent democratization and rapid privatization, shifting from government control to open markets. This allowed for the growth of private capitalism and the entry of Western corporate businesses.