The COE clearing price is set at the highest losing bid plus $1. Therefore, a PAYB system will not lower COE prices.

Furthermore, the COE bidding process is transparent and open. Bidders can observe the prevailing bid price in real-time. The majority of bids are made within the final hour of bidding, which suggests that bidders are closely monitoring the clearing price and making bids based on their willingness to pay, whilst avoiding paying more than necessary. The large majority of bids for cars are also clustered within a small range.