Interest rates... possibly

Example.  Consider a hypothetical economy using Bitcoins exclusively.  Assume for arguments sake that Bitcoin the rate of deflation is stable at 3%.  This means that if a person keeps their coins they get a nominal rate of return of 0% (real rate of 3%).  Now suppose someone would like to borrow some money.  You would only allow them to borrow money at some value greater than 0% which is greater than 3% real.  This effectively puts a lower limit on interest rates.

This could be could be good or bad.  It's good if it puts a cap on governments spending money they don't have.  It's bad if someone can't start a business because they can't get a loan.