Asia’s Missing Women: Shaping public debate on the security implications of imbalanced sex-ratios

Submitting Institution

University of Kent

Unit of Assessment

Politics and International Studies

Summary Impact Type


Research Subject Area(s)

Medical and Health Sciences: Public Health and Health Services
Studies In Human Society: Sociology, Other Studies In Human Society

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Summary of the impact

Den Boer's research into the relationship between extreme gender population imbalances and state security has shaped public and political debate within national and international media, influenced public policy and political campaigns, and affected the provision of data services within the Organisation for Economic Co-Operation and Development (OECD). The researchers' argument regarding Asia's missing women continues to inform journalists', NGOs', institutions', policy makers' and the wider public's understanding of the role played by gender imbalances when assessing state stability and security in situations as diverse as gendercide in Asia, youth uprisings and revolts, and gang rape in India.

Underpinning research

Dr. den Boer's research into the relationship between gender, demography, and security was conducted at the University of Kent from 1998 to the present and co-authored with Professor Valerie Hudson (Texas A&M). This co-authored research project (with equal contributions by both authors) resulted in a 2002 article published in International Security, a book manuscript (Bare Branches: The Security Implications of Asia's Surplus Male Population, 2004) and subsequent research articles and policy papers (including a well-cited piece in the Woodrow Wilson Center's Environmental Change and Security Program Report). This research, which examined the effects of severe gender imbalances in populations as a result of sex-selective practices, (including abortion, infanticide, and differential care given to infants and children), demonstrated the following:

  • A dearth of females (referred to as `missing women') has the potential to destabilise society, leading to reduced prospects for peace, democracy, and international security. Sociologists, demographers, and anthropologists studying the phenomenon of Asia's missing women had emphasised the effect of infanticide and sex-selective abortion on the reduced availability of marriage partners and the changes that this would have on kinship practices in affected states. Bare Branches argues that the effects go far beyond marriage squeeze: states with a severe gender imbalance in the population are more likely to be more violent internally and externally with the result that such states are less secure and of greater concern in international relations.
  • Drawing on historical cases as well as contemporary case studies including China and India, this research utilised historical process tracing to establish a causal link between `bare branches'—males who are denied a stake in societies—and increased violence and insecurity, including violence against women, increased high risk behaviour leading to increased criminality, riots, rebellions, and the potential to threaten state security. The increased violence within the state has an impact on state governance: states with high sex ratios and large numbers of missing men among the adult male population (particularly ages 15-35) are more likely to use authoritarian measures to maintain or restore stability, thus reducing prospects for democracy.
  • The research also pointed to the structural violence against women which results from the undervaluing of women inherent in state-controlled fertility practices and further discredited economic theory-based arguments which posit that a decreased supply of women would result in a higher value and increased status for women.

The body of research thus emphasised the need for policy makers to take gender demographics into account when assessing the security of states.

References to the research

1. Valerie M. Hudson and Andrea den Boer, `A Surplus of Men, A Deficit of Peace: Security and Sex Ratios in Asia's Largest States', International Security, 26, no. 4 (Spring 2002): 5-38. Reprinted in New Global Dangers: Changing Dimensions of International Security, Michael E. Brown, Owen R. Coté Jr., Sean M. Lynn-Jones and Steven E. Miller, eds., 337-370. Cambridge and London: MIT Press, 2004. International Security is one of the top ranked journals for International Relations (consistently scoring in the top five).


2. Valerie M. Hudson and Andrea M. den Boer, Bare Branches: The Security Implications of Asia's Surplus Male Population. Cambridge, MA: MIT Press, 2004. This book won the category of Government & Political Science in the 2004 Professional/Scholarly Publishing Annual Awards Competition presented by the Association of American Publishers, Inc., as well as the Otis Dudley Duncan Award presented by the Sociology of Population section of the American Sociological Association (ASA) in 2004. Bare Branches was translated into Chinese (complex characters) and published in Taiwan in 2005.


3. Valerie M. Hudson and Andrea M. Den Boer, "Missing Women and Bare Branches: Gender Balance and Conflict," Environmental Change and Security Program Report, 11 (2005): 20- 24.

4. Valerie M. Hudson and Andrea M. den Boer, `China's Security, China's Demographics: Aging, Masculinization, and Fertility Policy', The Brown Journal of World Affairs XIV, no. 2 (Spring/Summer 2008): 185-200.

Details of the impact

[Numbers in square brackets refer to corresponding sources in section 5 to corroborate the impact]
  1. Impact on public and political debate via international media
  2. The authors are at the forefront of the debate in two key areas: (1) the effect of high sex ratios on gender based violence (particularly following new population policy announcements in China and the effect these may have on gender relations or prospects for social stability [see 5.3], or specific events such as the December 2012 gang rape in India and the way in which this violence resulted from the high sex ratio in Delhi [see 5.1 and 5.2]); and (2) the debate regarding the security risk of populations with a large male youth bulge (journalists consulted the authors as the Arab Spring events unfolded, seeking predictions for the possibility of similar uprisings in China [see 5.4]). Through numerous interviews on television, radio, and in press, as well as through Opinion Editorials and other media outlets throughout North America, Europe, and Asia, Dr. den Boer has shaped understanding and increased awareness of the impact of gender selection and gender based violence on states (The authors have been interviewed, and/or the book referenced in the arguments of more than one hundred newspaper articles, internet discussions, blogs, or other media since 2008). The Bare Branches argument has been widely disseminated and its findings adopted by journalists, which has in turn led to adoption by NGOs (Oxfam and the Gendercide Awareness Project have drawn on the Bare Branches text and argument), individual bloggers (including foreign policy blogs, see for example,, and even a musician/composer [see 5.6] seeking to express the negative consequences of sex selective abortion—the composer, Pia Palme, commented that after reading a discussion on the book Bare Branches in an Austrian newspaper, she bought it and read it, and explained that `It was a great source of inspiration for the piece'. Bare Branches research has moved public and political debate beyond initial discussions of the marriage squeeze resulting from a dearth of females of marriageable age to arguments examining the wider societal and international impact of skewed sex ratios.

  3. Impact on public and political debate via international organisations
  4. The policy briefing, `Missing Women and Bare Branches: Gender Balance and Conflict' published in the Environmental Change and Security Program Report (a journal sponsored by the Wilson Center and the United States Agency for International Development) has been utilised by international bodies such as the Organisation for Economic Co-operation and Development (OECD). The OECD database, which is used by institutions, scholars, and policy makers throughout the world to calculate gender equity within developing states, drew on the 2005 policy report [3.3] in its 2009 and 2011 Social Institutions & Gender Index (SIGI) in order to evaluate the level of gender discrimination and the physical security of women within many of the states in the database [see 5.7]. Furthermore, the United Nations Population Fund has adopted the language and argument of Bare Branches, even referring to unemployed `surplus males' in high sex ratio populations as `bare branches' in their reports [see 5.8]. Bare Branches research was the first to highlight the need for policy makers to recognise the need to examine gender issues when assessing the security of states and thus has made a significant contribution to understanding and practice in this area.

  5. Impact on political campaigns and public policy

Research from Bare Branches has been used to support international (`All Girls Allowed') and national political campaigns (`Defend Girls' in Canada) [see 5.9] against pre-natal sex selection, as it offers support to the arguments that skewed sex ratios have the potential to destabilise societies. This research is thus affecting public debate and attempting to influence public policy regarding the politics of sex selection and gender-based population policies—the US based `All Girls Allowed' works with schools, churches, NGOs, and individuals to raise awareness about gendercide in China, rescue abandoned females and promote the well being of female infants in China.

The US government has also drawn on Bare Branches research to examine the effect of `surplus male' violence in China in its US Congressional-Executive Commission on China in 2009 and 2011 utilised Bare Branches to suggest that the large male population in China could pose a threat to social stability in the state [see 5.10]. Bare Branches research is therefore influencing government understandings of the relationship between population and violence/security.

Sources to corroborate the impact

Sources for impact on public and political debate via international media

  1. Debasish Roy Chowdhury, `Deadly demographics: Women face grim odds in male-heavy societies like China, India', South China Morning Post, Tuesday, 29 January, 2013, at male-heavy-societies-china-india
  2. [`Societies with abnormal sex ratios are considered inherently less secure. As Hudson and Den Boer find, the men who get to marry in such settings tend to have higher socioeconomic status. Those who can't are poorer, less educated and marginally employed. With little to lose, they exhibit a greater propensity for violence and more reckless behaviour, especially when they band together. Almost all the Delhi gang-rape suspects fit this description...']

  3. Anjani Trivedi and Heather Timmons `India's Man Problem', January 16, 2013, The New York Times/International Herald Tribune, Global Edition, at [`A much-cited 2002 study, "A Surplus of Men, a Deficit of Peace," by Valerie M. Hudson and Andrea den Boer, contends that a gender imbalance in Asian countries, caused by a shortage of marriageable women, results in higher rates of crime, including rape, committed by young unmarried men... "Internal instability is heightened in nations displaying exaggerated gender inequality, leading to an altered security calculus for the state," the authors wrote in 2002, and reiterated in a book on the subject. Their conclusions are even more true today...']
  4. Niall Ferguson, `Men Without Women: The ominous rise of Asia's bachelor generation', Newsweek, 6 March 2011, at [`Political scientists Valerie Hudson and Andrea den Boer warn that China and India could be the next countries to overdose on testosterone...']
  5. Kathleen E. McLaughlin, `Why China Won't Revolt', Global Post, 5 March 2011, at [`Andrea den Boer, co-author of the 2005 book "Bare Branches," an in-depth investigation of surplus males and related potential security issues in Asia, said China's situation is different than that of Egypt, which suffers from what is know as a "youth bulge"...']
  6. `Gendercide: The worldwide war on baby girls: Technology, declining fertility and ancient prejudice are combining to unbalance societies', The Economist, 4 March 2010, at [`In Bare Branches, Valerie Hudson and Andrea den Boer gave warning that the social problems of biased sex ratios would lead to more authoritarian policing. Governments, they say, "must decrease the threat to society posed by these young men. Increased authoritarianism in an effort to crack down on crime, gangs, smuggling and so forth can be one result.']. This particular article has been translated into Chinese and is available on numerous Chinese internet sites, such as
  7. Bare Branches, Secular Requiem and Space Arrangement for 2 solo voices, two vocal ensembles via audio score, and percussion, Pia Palme, Composer, with a text by Anne Waldman. World premiere, commissioned by e_may for Vienna Modern. Performed 25 October 2012 in Vienna. Salome Kammer, Annette Schönmüller solo voices/Ensemble of the Vienna Chamber Choir, Director: Michael Grohotolsky/Ensemble of the Vienna Youth Choir Music School Vienna, Director: Andrea Kreuziger/Percussion, Berndt Thurner. Available at branches-texts/. [The composer refers to Bare Branches as the inspiration for the composition].
  8. Sources for impact on public and political debate via International Organisations

  9. The policy-oriented article published as `Missing Women and Bare Branches: Gender Balance and Conflict' in the ECSP (Environmental Change and Security Program) by the Woodrow Wilson International Center for Scholars in Washington D.C. has been used by the OECD in its Social Institutions & Gender Index (SIGI). See, for example, the information at;; OECD, "Equity Indicators", in Society at a Glance: Asia/Pacific 2011, OECD Publishing, 2012. (On page 66 of this report, the OECD explains that they have modified the sex ratio for children based on Bare Branches research: `The sex ratio is computed mainly for the 0-4 age group since that presents a better reflection of the gender bias. Even though typically more boys are born than girls, the boys have a higher childhood mortality rate, which virtually cancels out the numerical advantage at birth by the age of five (Hudson and Boer, 2004)').
  10. The United Nations Population Fund summarises the argument of Bare Branches in its 2012 report Report of the International Workshop on Skewed Sex Ratios at Birth: Addressing the Issue and the Way Forward, Ha Noi Vietnam, October 2011, at
  11. 2012/Report_SexRatios_2012.pdf. [`The consequences are already becoming visible. There are reports of abduction, trafficking and polyandrous marriage. Men will marry at older ages, meaning that the age gap becomes larger. Cross regional marriages are increasing, which means that women move to a place where they have no support system, although it may also have some positive effects, for example, if the caste system is given less value. It may also mean that poorer men will be less able to marry, and in the worst case scenario it will lead to large numbers of men who are both unemployed and unmarried ("bare branches"), which might lead to increased violence. Women may turn away from marriage, exacerbating bride shortages'].

    Impact on political campaigns and public policy

  12. Defend Girls—A Canadian Campaign to stop sex-selective abortions: selective-abortion/. Cites the Bare Branches book as it argues that `populations with higher proportions of men to women can be unstable and violent'.
  13. Congressional-Executive Commission on China, Annual Report 2011, 112th Congress, First Session, 10 October 2011, at [`Some social and political scientists argue that large numbers of ``surplus males'' could create social conditions that the Chinese government may choose to address by expanding military enlistment'—with footnote to Bare Branches]