As the title of this question states, how much bitcoin is 'lost' (the private keys are not stored by any individual, and so will theoretically never be spent again)? I'd be looking for a percentage per year, ideally. Are there any stats on this anywhere?
Does it matter that Bitcoin is a deflationary currency, since bitcoins can be lost but cannot created again? It seems like this might encourage hoarding.
Does it vary much from other coins? Is if very different from the amount of fiat currency lost or destroyed unintentionally?