Instability Without Block Rewards

Resources

Paper: On the Instability of Bitcoin Without the Block Reward

Problem

Assume the longest chain head has 100 units of tx fees, and the next block is 5 units. Instead of mining the next block to grab the 5 units. A elfish miner would split the previous chain head in half, claim 55 units for themselves, and give 50 units for the next miner.