Experimental Design
We test crowding-in and crowding-out claims using a large-scale, big data field experiment. We will buy advertisements on Facebook to advertise donations to real food banks from New York City that are either government funded, or donation funded. Respondents from the NYC area will be targeted to keep the experiment regionally focused and at the same time ensure experimental realism. We will use Facebook’s online advertising facilities and randomly allocate groups of Facebook users into three experimental conditions, thereby manipulating the following funding information: 1) government funded, 2) donation funded, 3) no such information. Randomization will be done on a cluster leve of usersl, stratified by age, gender and zip code. A total of 600 clusters will be composed. Subjects within clusters will be repeatedly exposed to donation advertisements for 24 hours.
No individual-level date will be collected. For those who actually clicked the advertisements, they will be directed to a webpage on the School of Public Affairs and Administration (SPAA) at Rutgers University website, called “The SPAA Food Bank Observatory.” On this webpage, visitors will be informed of the purpose of the study and provided with a list (depdening on the experimental condition) of either government funded or primarily donation funded (or all) food banks in NYC, and encouraged to donate money to them (i.e., depending on the exprimental condition, three versions of this webpage exist). The food banks listed on the websites are all real food banks that operate in NYC, as collected through the National Center for Charitable Statistics (NCCS).