The Spanish are doing an interesting experiment: In Spain They Swap Money for Time, essentially allowing time-banks.
While the article (IMHO incorrectly) wonders whether there is anything anti-capitalist about the ideas (I don’t think they are), there is nothing intrinsically wrong with using a different currency to money. The problem typically lies with governments, which rely on
- skimming economic value-add activity (sales tax, GST, VAT, BTW, MwS, etc) to raise revenue;
- applying monetary controls, usually exerted by an independent central bank.
So the actual issues that need to be resolved are really quite funky. Of course you can give and charge interest on time, and you can tax it – but the taxing does not immediately translate into government revenue. If you wish to maintain a form of sales tax, then either people will have to owe the government a fraction of their time, or there needs to be a conversion to money.
If the government were a participant in the same time-economy, it could use the “time revenue” it raises to get things done, either directly (same people doing part-time work for the community) or indirectly (time “spent” through other companies in the system).
While money is not a necessity for an economy to work, it is a convenience – a convertable/neutral common currency. Having multiple currencies is generally not liked by governments as it affects their control, regardless of the merits. Just think of countries where the USD or EUR is the effective currency because the local one has become worthless (with huge inflation problems). Either that, or barter-style trade tends to pop up when countries are in tough economic times. People do what is practical to get by. But if authorities choose to actively allow/promote this activity and adjust the government processes to work with it, I think it can be made to work.