Cohort ID: cohort number (group of 6 or 8 subjects)
Period: decision period
Subject: subject number
Q: stocking quantity in push/pull, prebook in APD contracts
W: wholesale price in push/pull, regular wholesale in APD contracts
DW: discount wholesale price in APD contracts
Prod: production amount in APD contracts
Reject: binary variable for rejection (1 is reject).  In APD alternative, this represents the rejections from either role, therefore, to get retailer rejections, subtract sReject (supplier rejections)
sReject: binary variable for supplier rejection in APD alternative (1 is reject)
D: realized demand
isRetail: binary variable for role, 1 is retailer, 0 supplier
Contract: contract type, 1 push, 2 pull, 3 APD, 4 APD alternative