Edit: Also there is no duplication of work between pools or solo miners because the block you are working on contains the address to be paid the block reward.
I'd like further clarification on the claim that different pools/soloers have no duplication of work between them. Perhaps I'm just misreading, but there's no coordination between them. Within a given pool, different nonce ranges can be doled out to avoid duplication. And sure, there's a fair likelihood of relatively little duplicated work across different pools/soloers due to the vast problem space. But relatively little is not the same as none.