@Red

Here are different kinds of LETS. There are Credit Limited LETS, with for instance 1000 for each, -500 / +500 limits of money for each individuals, and of course UD.

BitCoin as (his first money system that should take another name than the P2P tool itself) is a limited Credit LET like.

But SCEC is much more near a DU since it give a fixed amount of money to each participant (so much more than 5% / year, but with decrease in time).

In fact to reach 5% / year, with a fixed amount of money f, it needs :

f / (f * y) = 5% => Y = 1 / 5% = 20 years to reach it... See graph

Of course LETS users understand quickly what is a DU, but they stated often from just a few years with few participants, the initial fixed amount of money is enough without visible problems, since 5% / year, only double the monetary mass for a 15 years period (1,05 ^15 = 2).

It depends generally of the SEL system, number of members, period of existence etc... Each money system has his own history of experience.