Plastic Grocery Bags—The Beginning.
The plastic grocery bag, also known as a gusseted t-shirt bag, was first introduced 50 years ago. It became pervasive in supermarkets throughout the U.S. in the late 1970's. Today approximately 40,000 supermarkets utilize $1.3 billion worth of plastic grocery bags. Plastic grocery bags became an indispensable supply item for supermarket chains because they are so inexpensive relative to the main alternative—paper bags. Specifically, a plastic grocery bag is about ⅙th the cost of a paper bag. Because of this cost disparity the plastic grocery bag is now 85% of a supermarket's bag cost and paper bags, once the bag of choice, are now only 15%.
The cost disparity and resultant dominance in supermarket use of plastic grocery bags is important as background because it speaksanswer in the questionnaire but refused to participate in this qualitative study.

Data collection
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Data collection took place between 12 and 18 months after distributing the booklet through semi-structured interviews at the participants' homes. Two female researchers (AS, NC) working at the rheumatology research department of a specialized hospital in the Netherlands conducted the interviews. The equipment we used to record the interviews provided both audio and video tapes. However, before the start of the data analysis we decided for pragmatic reasons to use only the audio tapes. Alternately, one of the researchers guided the interview and asked the questions, while the other researcher made field notes. In two cases, the partner of the participant was present during the interview. Both researchers were also responsible for the data collection in the