Costs of changing sex

In class we looked at certain monoecious plants that are able to change sex as they grow - and at an explanation for why this should occur and why the change should always be from male to female. A few animals can also do this sequential hermaphroditism but it is relatively rare as a strategy. In a recent paper in Am Nat two Yale scientists ask why the strategy isn't more common. One explanation would be that the costs of changing sex outweigh the benefits. The conclusions of their study are not buried deep in the paper but right there in the title:
Costs of Changing Sex Do Not Explain Why Sequential Hermaphroditism Is Rare

The RR Warner in the acknowledgements and numerous citations is, of course, UCSB's Bob Warner who works, amongst other things, on sequential hermaphroditism in fish

Also, if you'd like to read the original Nature paper describing the Papaya story I mentioned you can find it here:
A primitive Y chromosome in papaya marks incipient sex chromosome evolution