From a Social Credit perspective, economic efficiency in physical terms means producing whatever we need to survive and flourish with the least amount of human labour and resource consumption.
Thanks to technological advances and modern industrial technique, it is possible for us to produce all that we need while calling on a small and continually decreasing portion of the labour force. As an example, it has been widely reported that, as part of the 'fourth industrial revolution', 50% of American jobs will be automated within 20 years.
We can either accept this state of affairs as a benefit, because it increases the time we could be spending in leisure (i.e., self-chosen activities) or, if we insist that everyone must work and that the economy must provide everyone with a job, we must devise ingenious methods of having people 'dig holes and fill them up again'.
As it stands, a good deal of the work that is done in the modern economy is undertaken more out of an interest to distribute incomes and to forestall social chaos than to produce useful goods and services. Much work in the formal economy is wasteful, useless, redundant, and/or destructive. My favourite example of this are the people whose job it is to help other people find jobs: employment counsellors.
Social Credit, through its provision of a dividend to each citizen regardless of his employment status, allows us to opt for the former situation because it would permit those whose labour is no longer required in the formal economy to retain access to goods and services without taxing or penalizing anyone else.
Surely the environmental and social benefits of increased leisure and the elimination of wasteful production and consumption are self-evident.
Adopting a Social Credit financial system would be the single greatest thing that could be done by those who are concerned about 'green' issues: pollution, sustainable consumption, deforestation, etc.
While it is true that work in the formal economy can be a source of dignity, status, social connections, etc., it can just as easily be a source of denigration, oppression, and alienation. I don't think that there is anything magical or irreducibly positive about paid work. The non-economic benefits that might be had from work could also be obtained outside of the formal economy by the types of activities that people would freely undertake in a Social Credit society.
Apparently, in the Medieval economy of Catholic Europe, the average peasant could survive with only 15 weeks of labour per year and he also enjoyed over 150 holidays per year ... all of this leisure in a pre-industrial society. And yet the sky did not fall because people had so much time on their hands. Instead, they spent their leisure in building the great Cathedrals, in festivals and theatre, in charitable and social works of various kinds, and in a host of other activities.
As far as the labour theory of value is concerned - and quite irrespective of its origins or supporters - it simply cannot be sustained today when machines are doing more and more of the work.
The number one factor of production is the real capital, with labour acting more and more as catalyst. Real capital owes its tremendous productivity to the unearned increments of association bound up in mechanical, electrical, digital and other types of associations. These are gifts of nature and of the scientists, engineers, organizers, etc, of preceding generations. They owe nothing to the efforts of present day labour as such.
I've elaborated on these aspects of Social Credit teaching here: