The unit of analysis of the study is the individual firm. The population of this study consists of all EMS ISO 14001 certified manufacturing firms in Malaysia. The term “firm” here refers to companies as well as individual units or sites within companies. ISO 14001 certified firms were selected because they are expected to be embarked in the adoption of green purchasing initiatives. This is supported by the studies of Darnall, Jolly and Handfield (2006), Sroufe, (2003),
and Zhu, Sarkis, Cordeiro, and Lai (2008). A sampling frame is a list of all elements in a population (Sekaran, 2003). For this study, the sampling frame represents all ISO 14001 certified firms in Malaysia. The sampling frame was obtained from SIRIM organization in addition to the Federation of Malaysian Manufacturers (FMM)directory 2007 of Malaysian manufacturers (FMM2007). These two sources provided a sampling frame