Yields are meant to repay the providers of capital for the risk of tying up their available liquidities into risky projects. The concept is related to the existence of time preference of money: a 1$ today is worth more than a 1$ tomorrow, because lending it entails lost consumption and investment opportunities and because that dollar is subject to inflation. Therefore the only theoretical way in which an interest would be zero, is if the perceived risk of the issuing entity is zero. If this is mesmerizing, than how would one explain the negative nominal yields on Swiss bonds ?
