We start here with the observable premise that 'Corbynomics' is not an approach founded in Soviet Communism - there is nothing in the programme that proposes the collectiviastion of industry, the management of the economy through non-market means or a focus on production as a proxy for economic growth (even to the point of that production becoming value-destroying rather than value-creating).
Instead the programme of 'Corbynomics' focuses on state-determined priorities, the rejection of 'excess profit' and the use of a sovereign currency to allow the increase in the money supply (or printing money as some describe it). In its essentials the approach takes the view that those who 'have' should make larger sacrifices in the wider interests of society - that austerity should be targeted at the rich.
A central element of all this - sitting alongside the printing of money - is the idea that money only exists so that governments, the state, can collect taxes. In this worldview the only money we are entitled to is that which government permits us to have after it has taken the taxes needed to undertake the work of the state (or, if you subscribe to the MMT fallacy, to prevent the production of money creating inflation).
Here's Richard Murphy, self-described creator of 'Corbynomics':
I would suggest that we don’t as such pay taxes. The funds that they represent are, I suggest, in fact the property of the state. After all, if we give the state the power to define what we can own, how we can own it and what we can do with it – and we do – then I would argue that we also give the state the right to say that some part of what we earn or own is actually its rightful property and that we have no choice but pay that tax owed as the quid pro quo of the benefit we enjoy from living in community.The essential idea here is that the government is better equipped than individuals or markets to make the right choices in the interests of the community. And this is pretty much an idea that was first developed and actioned in Italy. In rejecting 'Bolshevism' and accepting profit as a 'necessary incentive', the Italians developed an economic strategy that was centred on the idea of directing private enterprise rather than taking it over:
...private enterprise in the sphere of production is the most effective and useful instrument in the interest of the nation. In view of the fact that private organisation of production is a function of national concern, the organiser of the enterprise is responsible to the State for the direction given to production. (Benito Mussolini, The Doctrine of Fascism 1935)
With this in mind the Italian state not only created huge corporate conglomerates with horrendously complicated governance but engaged in a series of grand campaigns focused on security of supply in food, in basic industry and in finance. The result of this is familiar in that joke about Mussolini getting the trains to run on time (he didn't) and in wonderful but pointless achievements such as draining the Pontine Marshes.
So looking at 'Corbynomics' we see the same appeal - that the state is greater than the sum of its parts, that only courageous leaders can direct investment so as to deliver economic, social and environmental betterment in equal part, and that the interests of business is subservient to the state's objectives. Or, as Mussolini aptly summarised:
All within the state, nothing outside the state, nothing against the state.
Because the state already, at root, owns everything there is no need to bother with such things as nationalisation. Instead the state uses instruments already available to it - taxes and the production of money - to direct business and industry in the direction that the state's leaders have determined. In doing this the state, rather than adopting the crude ownership model of classic socialism, chooses instead to take 'strategic stakes' in industry via a National Investment Bank and to adopt via this route the power to appoint to boards of directors.
The problem is that this sort of approach becomes ever more centralised in those courageous leaders of the state, increasingly exposed to corruption and so sclerotic as to act as a drag on the economy:
“...a never‑ending stream of officials passed through Mussolini’s office each day to receive his orders, though he had no means of checking that his orders were carried out. Officials generally pretended to obey and took no action at all. His chief preoccupation was to make sure newspapers reported that he had given orders on every conceivable topic including sports. There was a jungle of overlapping bureaucracies where Mussolini’s orders were constantly being lost or purposely mislaid. Any fascist party official could issue an order purporting to come from Mussolini, as its authenticity was hard to check. By trying to control everything, he ended up controlling very little.”
Now people have observed that modern technology makes totalitarianism easier. But, under 'Corbynomics' - with state-directed investment and high corporate taxes constraining private investment - we still see a situation where investment decisions are made by non-risk-taking experts rather than by risk-taking entrepreneurs. We have to trust that those experts will make the 'right' or 'best' decision, even though they do not have all the information and are not truly accountable for that decision. This problem is compounded because the progenitors of 'Corbynomics' insist that its objectives encompass social and environmental factors as equal 'partners' with considerations of economic betterment.
The ideas of 'Corbynomics' are not a direct parallel with the core doctrines of Fascism (at least as set out by Mussolini and philosophers like Gentile). However, they hail from the same birthplace, from the idea of a brave and activist state. Indeed, if we are to search out the closest equivalent to Richard Murphy's 'Courageous State' and the ideas that sit in the heart of 'Corbynomics', the best place to look is at Mussolini's renewed dictatorship after 1925. This was the triumph of Il Duce's activist government - praised by Sidney & Beatrice Webb, lauded by H G Wells and G B Shaw, endorsed by FDR, and approved of by Winston Churchill. But I guess we're not allowed to call it Fascism?