Annoyingly, I don't have any exact figures to hand so can [edit: only] speak in general terms. This is no doubt partly because the post-war reconstruction of the Soviet Union was almost as chaotic as the evacuation itself.

After the war some enterprises and their staff may have moved back west but the majority appear to have remained in the east. The war had vastly progressed the hesitant 1930s progress of 'opening up' the east, capping the emergence of a modern industrial economy.

Population centres in the Urals and Siberia (eg Novosibirsk, Tomsk and, of course, Magnitogorsk) swelled permanently during the war. Industrial expansion followed suit, with the evacuated western enterprises establishing these regions as key industrial centres: output more than tripling over the course of the war.

It was the outputs from these factories (alongside reparations from the defeated Axis nations) that largely fuelled the impressive, if slow, reconstruction of European Russia in the post-war years.

A particular case to note is the defence industries, which were almost entirely retained in the east. The lessons of the German invasion saw the centre of gravity of the Soviet defence industry shift to the Urals. The expansion of this in the post-war years (with new jet, nuclear and rocket industries) led to the creation of new 'closed cities' in purposefully remote locations.

Overall, the evacuation of 1941 had the long-term impact of spurring growth and investment in the western regions. The 1940s transformed much of the region and made it both an important industrial centre and the home of the Soviet defence industry.

Sources

• Mark Harrison, The Soviet Union after 1945: Economic Recovery and Political Repression

• Alec Nove, Economic History of the USSR

• Eugene Zaleski, Stalinist Planning for Economic Growth

That's coming from my personal experience. I was born in Almaty, Kazakhstan. It was part of USSR back then. If you find it on a map you can see it's quite remote, far from Eastern front and potential Japanese one. We still have quite a bit of factories that were moved during WWII. I grew up next one of them, Kirov factory. It was still functioning in early 2000s when I left.

Yes, (almost) all evacuated factories moved back, but there's a twist. For example, famous Kharkov's plant №183 (first to produce T-34 tanks) was evacuated to Nizhny Tagil in 1941. It was rebuilt in Kharkov after the war and remained one of the tanks producing centers of the Soviet Union (T-64 and T-80 were conceived there, for example), but its offspring - plant at Ural Mountains - wasn't demolished and in turn also became alternate producing center of the tank industry, and gave the Soviets T-72 and T-90.

This can be said for almost every evacuated factory, in place of one Soviet Union got two after the war.