Neil Carrier is Associate Professor in Social Anthropology at the University of Bristol, UK. He has conducted much research into the production, trade and consumption of khat in Kenya and beyond, as well as further research into the theme of drugs, including a current project on cannabis in Africa. Wider interests include film, photography and urban development in Kenya. Lisa L. Gezon is Professor and Chair of the Department of Anthropology, University of Alabama-Birmingham, USA. She has studied political ecology and protected area management in Madagascar. She developed an interest in the production, trade and consumption of khat in northern Madagascar because of its perceived threat to the protected forest. She has also studied multiple subjects related to health and wellness on topics such as tourism, yoga and exercise on a bicycle-pedestrian trail.