Exploring sexual contact networks by analyzing a nationwide commercial-sex review website

  Assistant Professor Hiromu Ito(first author), Cooperating Researcher Keiko Shigeta, and Professor Taro Yamamoto of the Department of International Health and Medical Anthropology at the Institute of Tropical Medicine, Nagasaki University, together with Professor Satoru Morita of Shizuoka University (responsible author), have successfully analyzed part of the sexual contact network in the Japanese sex industry.

 ■Abstract 
  Understanding the structure of human sexual contact networks is vital in a broad range of disciplines, including sociology, biology, public health, and anthropology. However, sexual contact networks are yet to be understood because technical and privacy issues make it difficult to conduct accurate, large-scale surveys. In this study, we surveyed data openly available on one of the largest adult entertainment websites in Japan, where male clients (MCs) can write online customer reviews of female commercial sex workers (FCSWs). In particular, our investigation focused on a type of establishment called “soapland,” the only type of sex industry in Japan where sexual intercourse is publicly permitted. Soaplands are scattered throughout Japan, and the study website covers approximately 66% of them. Using such a vast amount of data on a nationwide scale, we clarified the network structure of commercial sex, characterized by small-world, scale-free, and disassortative mating properties. To study geographical characteristics, we compared the resulting network with three different artificially generated networks via the random rewiring of links. Moreover, we considered a simple epidemic model on the resulting network, and investigated whether it would be more effective to provide infection control measures to FCSWs or MCs. We determined that active FCSWs constitute an important pathway of infection propagation in commercial sex networks, but MCs also play an essential role as weak ties.

 ■Journal information 
Ito H, Shigeta K, Yamamoto T, Morita S. Exploring sexual contact networks by analyzing a nationwide commercial-sex review website. PLoS ONE. 17(11): e0276981, 2022.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0276981


▶This release is also available in Japanese.

List