> they collapsed because a state owned economy cannot grow at the rate needed to compete.

Uhm, no. It is a myopic and a highly lopsided point of view. The collapse of the Soviet Union was a combination of a few compounding factors:

– Soviet Union has come out of the WWII having been slightly less than completely devastated. The entire European part of the USSR, that had been the centre of the manufactoring and farming before the war, was razed into the ground. Larger and smaller cities, towns, villages – every single thing.

– Accounts vary, but the general consensus is that at least 27 million people have perished in the war (in trenches / battles, in Nazi concentration camps, tortured, gassed or burned alive or executed). Again, by varying accounts, at least 50 million more people have come out of the war being physically or psychologically (usually both) traumatised. The killed and the injured have comprised the most productive part of the USSR workforce before the war – out of a population of 140 million people before the war.

– A few waves of internal political represssions and witch hunting that have followed the war and up until Stalin's death have added to the number of overall casualties.

– It has taken the USSR nearly 20 years to return to pre-war levels of the production output. The vast majority of the population have lacked basic necessities all the way into mid-1960's or longer. Having rebuilt the economy, the government has focused on providing the general populace with free (oftentimes shitty, though) accommodation, free health, free education, full time employment and pension. By the mid-1970's, the majority of the population had had a roof of sorts over their heads (also of varying quality); still, it was a roof, and it was free of charge.

– Not only did the US come out of the WWII unscathed, it has also turned out to be the main beneficiary of the war. In exchange for help, the USSR (and the UK as well) were shipping convoys loaded with the gold bullion back to North American shores over the Arctic Sea. Even though the Nazi U-boats did succeed in the sinking of quite a few of the convoy ships, by the end of the war the US had become immensely rich with no material damage to the local economy. It is important to point out that, without the US (Canadian / UK and the allied help overall) assistance – that was absolutely crucial to the USSR survival in the first 2-3 years of the war – the USSR would have not lasted past 1941-42. The US was providing the USSR with everything, starting from machinery, armaments, munitions – down to army uniforms and preserved food. US made Studebaker US6 trucks were the single most frequently utilised military vehicle in the Red Army due to their availability and sturdiness throughout the entire war. Disappointingly, due to the current heated political situation, many ex-Soviet/Russian citizens live in complete denial of the importance of the US help in the WWII.

– In the following post-war years, the US has succeeded where the Soviet government has failed. Namely, in winning a psychological war and, consequently, in tricking and convincing the Soviet government into a believing that a nuclear conflict was imminent and inevitable. Which has resulted in the economic production nearly in its entirety having been funneled into defence and arms race at the expense of domestic needs. In the hindsight, the Soviet government could have ignored the threat, but they did not. Which was a grave mistake.

– A lesser, but not insignificant, factor was the Soviet Union throwing money away at establishing and supporting nascent, Soviet friendly, regimes and proxy wars in the post-colonial world that has not resulted in anything else other than flushing vasts of money down the drain.

– Towards the end of 1980's, a huge internal budget deficit caused by preceding factors had resulted in a death spiral and a complete economic and – predictably – political collapse of the Soviet Union.

The state run economy has actually done a very good job at recovering the country's economy in the first two post-WWII decades.