Applying the payment card approach to estimate the WTP for green food in China

This paper uses a payment card approach to reveal consumers' willingness to pay for green food in China. We first present a brief introduction of the payment card approach and introduce several methods to estimate the WTP with payment cards, which we subsequently use to estimate WTP values regarding green vegetables, green meat and green eggs in China. Our results indicate that consumers in big cities are willing to pay a higher premium for green food and that WTP values are relatively higher for more expensive food than for cheaper food. In addition, the ratios of premium to price range mainly between 25% and 50% and WTP values obtained from interval midpoint approach are relatively higher than those calculated by other approaches. --WTP,Payment card,Green food

On Content-centric Wireless Delivery Networks

The flux of social media and the convenience of mobile connectivity has created a mobile data phenomenon that is expected to overwhelm the mobile cellular networks in the foreseeable future. Despite the advent of 4G/LTE, the growth rate of wireless data has far exceeded the capacity increase of the mobile networks. A fundamentally new design paradigm is required to tackle the ever-growing wireless data challenge. In this article, we investigate the problem of massive content delivery over wireless networks and present a systematic view on content-centric network design and its underlying challenges. Towards this end, we first review some of the recent advancements in Information Centric Networking (ICN) which provides the basis on how media contents can be labeled, distributed, and placed across the networks. We then formulate the content delivery task into a content rate maximization problem over a share wireless channel, which, contrasting the conventional wisdom that attempts to increase the bit-rate of a unicast system, maximizes the content delivery capability with a fixed amount of wireless resources. This conceptually simple change enables us to exploit the "content diversity" and the "network diversity" by leveraging the abundant computation sources (through application-layer encoding, pushing and caching, etc.) within the existing wireless networks. A network architecture that enables wireless network crowdsourcing for content delivery is then described, followed by an exemplary campus wireless network that encompasses the above concepts.Comment: 20 pages, 7 figures,accepted by IEEE Wireless Communications,Sept.201