There are two popular models for issuance of distributed currency: Proof of Work and Proof of Stake.

The prevailing model, used by BitCoin, is Proof of Work (PoW). Proof of Work involves computing a solution to some computationally difficult problem. This has some known problems:

Miners compete for compute power, leading to a massive consumption of eletical power, for little or no societal benefit

Issuance follows a Poisson process, leading to irregular block update times and disrupting time-sensitive commerce

Mining compute power is aggregated in the hands of a few firms

Alternatives proposed are Proof of Stake (PoS), as well social-network consensus mechanisms such as the one used in Ripple. In PoS, a number of stakeholders coorperate to ratify a new unit of currency. Proof of Stake presents the tantilizing possibility of very rapid blockchain progression, which is strongly desired for an ecomerce platform.

One criticism of PoS is that it leads to wealth inequality. The ratifiers of newly issued blocks will tend to already possess a large balance, and provided they are compensated they will command even more wealth. To date, no analysis of the severity of this inequality has been made.

It is my view that the design of a cryptocurrency is social engineering, and this aspect of protocol design must be considered. Apart from analyzing capital lockup, I have not endeavored to model any other economic implications of the choice of issuance model.