The entire population of residents of Jamestown was used in the experimental market. Households were randomly assigned to the PM (Pivotal Mechanism), PR (Proportional Rebate) or UPA (Uniform Price Auction) mechanisms in 2007 and to the PM, PR or UPC (Uniform Price Cap) mechanisms in 2008. In both years, marketing materials were sent twice during March and April, with the exception that about 50% of the households who responded in 2007 being assigned the same mechanism in 2008 (recipients of the UPA in 2007 were assigned to the UPC in 2008), with the other 50% assigned to the other two mechanisms.

Because this is a field experiment, outside the more abstract but more carefully-controlled economics laboratory, the investigators could not control each individuals choice of whether to participate in the experiment. In this context, participation means that an individual chose to mail a reply card back to the Nature Services Exchange (at a URI address), whether or not they decided to make a monetary offer. Monetary offers were received either by personal check or by a credit-card authorization.

About 10-12% of residents decided to participate in the Exchange, netting about 8% of individuals making offers. This means around 87-90% or so chose not to respond. This participation rate is somewhat higher than in many marketing efforts for familiar businesses. For our analysis, this participation rate means that our data needs to be analyzed in two steps. One is a statistical evaluation of the factors that increased the chance that an individual would decide to participate. The other is a statistical model of the factors that increased the magnitude of the offers made by those who participated, while accounting for those who participated but chose to make a zero offer. Therefore, our statistical evaluation of the offers made is conditional on an individual having made a choice to participate.

Within the marketing materials, some individuals were given a discrete-choice (DC) opportunity, while other individuals were given an open-ended opportunity (OE), again using a random assignment process. The DC form presents individuals with one amount of money and the choice to agree to offer that amount, or to decline to offer that amount; individuals were not allowed to offer any other amount. The OE form presented individuals with a list of possible offer-amounts to choose among and also allowed the individual to name their own amount (fill-in the blank). In 2007, the OE form was either “high” with listed amounts between $35 and $120, while a “low” form listed values between $20 and $80 (we designated these lists as OEhigh and OElow, respectively). The DC form is expected by economists to generate higher values because it reduces the opportunity for an individual to strategize by choosing an amount that is lower than they would actually be willing to pay rather than forego seeing a farm-wildlife contract implemented.

In addition to data on the mechanisms and the DC or OE form of presentation, we also obtained information from a commercial marketing firm indicating each resident’s attributes for age, household income (or purchasing power), and information on whether the household had a record of donating to various activities or making mail-order purchases. Finally, each direct-mail solicitation to individuals described the farm-wildlife contract available for which that person was being asked to make a decision, including information on the number of acres under contract (7-18 acres; but always 10 acres in 2008), number of bobolink territories recently observed on the field (1-4), whether the parcel was visible from a main road (whether it had a “view”) and, for 2008 only, an explicit statement of the number of fledglings that might be expected to be raised in the field given the number of bobolink territories observed in a recent year.