Hi,

maybe someone can shed light on a question I am wondering about.

Empty blocks are usually found very quickly after a "normal" block. The explanation I have heard most is that miners will start mining an empty block while they still assemble the tx and merkle roots for the next "normal" block. Sometimes they get lucky in this short time.
The frequency of empty blocks would suggest this "short time" to be around 5 seconds, plus/minus 50% or so. This sounds like an awfully long time to get the normal block preparation done.
Is there something I am missing? Is the chance to catch the block reward with an empty block good enough to always mine on it for several seconds?

thanks for any insights