This book contains the tenth volume of the online journal Demographic Research, including all material published January to June 2004. The journal is published by the Max Planck Institute for Demographic Research in Rostock, Germany and aims to publish top-quality demographic research and related material and to encourage the development of an international community of people concerned with demographic research. This volume, as well as all other material, is available online (www.demographic-research.de) as open access material. This bound paper version is available on a print-on-demand basis through bookstores under ISBN-13978-3-8334-6942-8. For further information, please visit the journal web site.