Empty Block Mining

Professor of computer science and well-known bitcoiner, Jorge Stolfi, gives a simple explanation to why a miner would mine an empty block: “The transaction fees are an incentive for miners to include all the transactions that they can in their candidate blocks,” explains Stolfi. “However, a miner often can start mining a candidate for block N+1 even before he has seen what was included in block N. That’s because he only needs the hash of block N, and he often can get it very quickly by a certain trick. In that case, the miner must start with an empty block N+1, even if there are transactions waiting in his queue: because, without knowing the contents of block N, he cannot check whether those transactions are valid or not. If he is lucky, he may solve that empty block N+1, even before he finishes downloading the body of block N. That is why there are empty blocks.”