The rate of reported rapes is much lower in Japan than the United States. In a 1993 paper German sociologist and criminologist Joachim Kersten suggested date rape may be less prevalent in Japan compared with the United States because Japanese culture puts a lesser emphasis on romantic love and dating, and because young Japanese people have less physical privacy than their American counterparts, and in her 2007 book "Kickboxing Geishas: How Modern Japanese Women Are Changing Their Nation", American feminist Veronica Chambers questions whether date rape is under-reported in Japan because it isn't yet understood there to be rape. In the 2011 book "Transforming Japan: How Feminism and Diversity Are Making a Difference "Japanese feminist Masaki Matsuda argued that date rape was becoming an increasing problem for Japanese college and high school students.