An English auction is an ascending-price auction. For more details on this type of auction, see the Handbook section on English Auctions.
Parameters are configured in the right-hand panel: Parameters for Regime #1
Screen Capture: Configuration Screen for English Auction
Period length: This allows the experimenter to select the length of each auction period (2 minutes by default).
Closing rule: The experimenter may use the dropdown menu to choose between a hard or soft close.
- Hard close: When hard close is selected, the auction ends exactly at the end of the specified period length. This may enable a bidder to slip in a higher bid just before the end of the auction without giving other participants a chance to respond by increasing their own bid.
- Soft close: Selecting this option allows the bidding to continue indefinitely if bidding activity occurs within a defined time window at the end of the period. When a soft close is selected, 2 other windows are opened: Soft close threshold and Soft close extension.
- Soft close threshold: This box allows the experimenter to determine the length of the window at the end of the period during which the auction may be extended if a new bid is entered.
- Soft close extension: This box allows the experimenter to specify the length of time the auction is extended after each new bid at the end of the auction.
Minimum starting bid: Here the experimenter specifies the lowest possible first bid in the auction.
Minimum bid increment: Here the experimenter specifies the smallest possible difference between bids that is allowed in the auction.
Unit of divisibility for bids: Here the number by which every bid must be divisible is entered (select .01 to allow all possible bids).
Proxy bidding allowed: Checking this box will permit proxy bidding for each bidder. When proxy bidding is permitted, bidders may specify a price they are willing to pay in the auction so they will continue to out-bid other bidders until they have reached their proxy limit.
- Details: Clicking the details button will bring up the screen below which enables the experimenter to specify exactly those bidders who are allowed to use a proxy.
- Identify proxy bid: Checking this box will enable all auction participants to see when a bid is made by proxy.
- Proxy response delay: Here the experimenter may specify the amount of time a proxy will wait before entering a higher bid in response to another participant's bid (defaut is 1 second).
After setting these institution specific parameters, it is time to set up inducements by clicking on the Inducement tab. For details click here.