@jreighley The currency that is the most stable goes a long way toward providing a business the greatest degree of security and freedom. Both hostile speculation and get-rich-quick are tied to volatility. Minimizing volatility is at the heart of a security approach to currency and that’s been my impression of what the SAFE group has been aiming for.
Perish-ability does seem like something that could be phased in later to help increase stability. We already have long experience with the psychological equivalent. Coin is less perishable than cash and cash less perishable than card. We have more direct experience with the concept through options and life estates. But at launch it could seem like terminator seed. The time to phase it in might be after SAFE a dominant store of value. Phasing it in would create a premium on non perishable SAFE coins, but those coins too could be retired eventually. Adding the feature to existing SAFE coins as opposed to retiring them might seem like a hack. Maybe the perish-ability timer would get reset after every trade with a delay?