Sustainable consumer behavior is the sub-discipline of consumer behavior that studies why and how consumers do or do not incorporate sustainability priorities into their consumption behavior. It studies the products that consumers select, how those products are used, and how they are disposed of in pursuit of consumers' sustainability goals. From a conventional marketing perspective, consumer behavior has focused largely on the purchase stage of the total consumption process. This is because it is the point at which a contract is made between the buyer and seller, money is paid, and the ownership of products transfers to the consumer. Yet from a social and environmental perspective, consumer behavior needs to be understood as a whole since a product affects all stages of a consumption process. Consumer decision process The buyer decision process or consumer decision process is described in three or five stages. The basic, three stage model of consumption describes obtaining, consuming, and disposing of products and services. The study of consumer decision making expands these into five stages, first described by John Dewey in 1910: Problem recognition Information search Evaluation of alternatives Purchase decision Post purchase behavior Problem recognition Need and want recognition occur when a consumer senses a difference between what he or she perceives to be the ideal versus the actual state of affairs. Information search There are three key sources for searching information: personal, commercial, and public sources. Mass media, which is a public source, increasingly provides information about the environmental costs and benefits of consumption. Consumers become aware of such costs and benefits through these sources. Evaluation of alternatives In this stage, environmental concerns which are expressed as environmental costs, risks, and benefits, will contribute to the evaluation of options as the consumer decides what to buy. One way to evaluate more sustainable consumption is to consider the total customer cost which incurs in acquisition, use, and post-use phases. Purchase decision Consumers have to trade off the environmental benefits against other attributes such as price, performance, and design. In addition they may need to change their habitual manner of behavior. Post purchase behavior In this stage, maintenance, repair, use frequency, and type of use are of interest. For some key products such as homes, cars, and domestic appliances, much of the sustainability impact accrues after the purchase phase during use or post-use. Post-purchase behavior may also include disposal where consumers can keep, reuse (for