Bare Branches

From Belfer Center Studies in International Security

Bare Branches

The Security Implications of Asia's Surplus Male Population

By Valerie M. Hudson and Andrea M. den Boer





What happens to a society that has too many men? In this provocative book, Valerie Hudson and Andrea den Boer argue that, historically, high male-to-female ratios often trigger domestic and international violence. Most violent crime is committed by young unmarried males who lack stable social bonds. Although there is not always a direct cause-and-effect relationship, these surplus men often play a crucial role in making violence prevalent within society. Governments sometimes respond to this problem by enlisting young surplus males in military campaigns and high-risk public works projects. Countries with high male-to-female ratios also tend to develop authoritarian political systems.

Hudson and den Boer suggest that the sex ratios of many Asian countries, particularly China and India—which represent almost 40 percent of the world's population—are being skewed in favor of males on a scale that may be unprecedented in human history. Through offspring sex selection (often in the form of sex-selective abortion and female infanticide), these countries are acquiring a disproportionate number of low-status young adult males, called "bare branches" by the Chinese.

Hudson and den Boer argue that this surplus male population in Asia's largest countries threatens domestic stability and international security. The prospects for peace and democracy are dimmed by the growth of bare branches in China and India, and, they maintain, the sex ratios of these countries will have global implications in the twenty-first century.


$40.00 X ISBN: 9780262083256 344 pp. | 6.125 in x 9.25 in


$35.00 X ISBN: 9780262582643 344 pp. | 6.125 in x 9.25 in


  • [A] well-documented study...


  • impressive and comprehensive account of sex ratios...

    The Wall Street Journal

  • ...Bare Branches has become a flashpoint for a debate about the link between sex ratios and security.

    New York Times

  • ...connects the dots of a huge demographic trend that carries international implications.

    The Christian Science Monitor

  • [E]xciting, innovative, refreshing...marks an important contribution at the nexus of the already burgeoning literatures addressing environmental and human security.



  • Bare Branches is a tour de force. It represents a groundbreaking contribution to the literature on gender and security studies. Hudson and den Boer call attention to the ticking time bomb of sex ratio imbalances, especially in East and South Asia, and its impact on the likelihood of domestic instability and inter-state war. All who address these issues in the future will need to contend seriously with the persuasive arguments made in this book.

    Rose McDermott

    Assistant Professor of Political Science, University of California, Santa Barbara

  • Bare Branches is an excellent book that represents a new approach to thinking about political stability and international politics. Hudson and den Boer draw from the life sciences to reveal historical patterns that other scholars have missed. They present comprehensive data on sex ratios and fascinating historical studies of social instability brought on by excess young males.

    Francis Fukuyama

    Dean of Faculty and Bernard Schwartz Professor of International Political Economy, The Paul H. Nitze School of Advanced International Studies, Johns Hopkins University

  • Bare Branches reveals a largely overlooked but important variable correlated with war and peace: high ratios of males to females. Through both historical and contemporary analyses, Hudson and den Boer show that in societies where women have low status, peaceful democracies are far less likely to take hold. All those who hope to understand the causes of war—in academe as well as in government—will have to be aware of these findings. A brilliant contribution to the literature on contemporary world affairs.

    Jessica Stern

    Lecturer in Public Policy, John F. Kennedy School of Government, Harvard University


  • Winner in the category of Government & Political Science in the 2004 Professional/Scholarly Publishing Annual Awards Competition presented by the Association of American Publishers, Inc.
  • Winner of the 2004 Otis Dudley Duncan Award presented by the Sociology of Population section of the American Sociological Association (ASA)