They are not like gold, silver, etc. that have intrinsic value. Their only value is from their backing by those issuing banks, ie backed only by U.S. dollars.Al68,
This is true for the moment at least, but if the US currency is devalued say 30% and people are used to dealing in Berkshares for .95 cents on the dollar, it is not too far of a stretch to suggest that they could at least regionally set their own exchange rate in the region based on Berkshares alone for participating members. It is all contingent on that magic ingredient, "trust", in return for goods and services, simple as that. I would dare to suggest that Berkshares could be used just like other valuable assets, gold, etc... in times of crisis. Of course control over the number of shares printed is important for the regional currency to hold it's value, just like it is with the run-away dollar. Print too many Berkshares and we are in the same ballgame all over again.
They will always be worth 0.95 U.S. dollars, unless they either become worthless because those banks go bankrupt, or they gain numismatic value due to rarity, which is a different matter altogether, and seemingly unlikely.