  Payment channel networks are supposed to overcome technical scalability
limitations of blockchain infrastructure by employing a special overlay network
with fast payment confirmation and only sporadic settlement of netted
transactions on the blockchain. However, they introduce economic routing
constraints that limit decentralized scalability and are currently not well
understood. In this paper, we model the economic incentives for participants in
payment channel networks. We provide the first formal model of payment channel
economics and analyze how the cheapest path can be found. Additionally, our
simulation assesses the long-term evolution of a payment channel network. We
find that even for small routing fees, sometimes it is cheaper to settle the
transaction directly on the blockchain.
