It was a mistake to mention the S-word, given how close it is to current politics; suffice to say that nothing Mussolini did was unprecedented or particularly against educated advice at the time. Creating closed currency zones with artificially mispriced currencies was certainly harmful but Germany, the USSR, the UK and the US did it too. Mussolini bears no special blame for things of this sort, in the context of the time. And indeed Italy did not have a basket case economy in 1940; with about the same population, its per capita productivity was about 75% the level of France. Mussolini was certainly not good for the Italian economy, but countries that performed much better in the war had worse economic policies. Italy's main economic problem was that it never fully mobilised, spending only in the 20% range of its national income on the war when everyone else was spending in the 40s or 50s. Italy contributed only about half of what it could have done.
He did terribly economics wise for a 22 year long dictatorship.
Let's compare all major in 1925 (in terms of 1960 US $) (approx. the time Stalin becomes absolute Dictator and Mussolini becomes one too, Hitler is still far away) & 1938(last pre-war year)
In 1925 Italy has a GDP of 18.50 Billion and in 1938 of 23.70 Billion (28% increase)
Germany has 45.00 and 77.20 (72% increase) - despite all the turmoil
USSR has 32.60 and 75.90 (132% increase) - despite all the unmentionables, maybe also partially due to it.
France has 36.20 and 39.20 (8% increase)
UK has 43.70 and 56.10 (28% increase)
Europe as a whole has 257.40 and 376.90 (46% increase)
Shows he did as good as the UK with a vastly lower Base. Italy started at 40% of UK and went on to remain the same in percentage terms. Though he did better than France, France has a base which was 70% more. Both Germany and USSR vastly out performed him.
I have not taken population into account for all countries.