1) If no transaction happened, then modelling the buyer's next bid on the market's last transaction results in an empty bid
2) The sellers from previous successful transactions, drop out of the market, while the buyer's don't. This is the exact opposite of what we want.
Emailed James about help with describing the algorithm formally and doing some analysis (maybe probabilistic or game theoretic). Obviously, he won't read my paper immediately, but any critical response from him, over the next week, would be good.