Lisa Cameron is a Professor in the Department of Econometrics and Business

Statistics at Monash University. Her research focuses on development issues

in Southeast Asia and China, and she regularly advises governments and

other agencies, including the World Bank and the Australian Department of

Foreign Affairs and Trade, on policy development and program evaluation.

Although the Chinese government has recently relaxed its One Child

Policy, the extent to which this will affect sex ratios, and therefore

crime rates, is unclear. Even if the new approach results in a more

balanced sex ratio, it will take at least a generation before this leads

to reduced competition in the marriage market. Consequently, current

marriage market pressures are likely to be sustained (and may even

worsen) in the short term, with the concomitant incentives to engage

in crime.

For more on this research, which was conducted with Xin Meng

(Australian National University) and Dandan Zhang (Peking

University), please see the full report, available on my website.

We analysed experimental and survey data from 959 rural-urban

migrant prison inmates and 299 non-inmate migrant workers from

Shenzhen, a city with a population of 15 million people in the

southern province of Guangdong, at the heart of China's

manufacturing boom.

We examined the extent to which:

China's One Child Policy, which was launched in 1979 and ended

in 2015, in combination with China's strong cultural preference for

sons, the availability of ultrasound technology, and female

infanticide and abandonment, has resulted in a highly skewed sex

ratio. By 2000 almost 120 boys were born for every 100 girls, and

by 2010 there were an estimated 30 million “surplus" boys in China.

China’s crime rate has increased dramatically over the past 30

years, from 7.4 crimes per 10,000 in 1982 to 47.8 crimes per

10,000 in 2014.

Crime rates in China have increased more than six-fold over thepast three decades, in part driven by China’s highly skewed sexratio. While there are many plausible reasons why excessmales result in an increase in crime, few have been directlytested.

Drawing on experimental and survey data, we find that theskewed sex ratio is associated with greater risk-taking andimpatience, which are each associated with increasedcriminality. However, we also find that the dominant wayChina’s sex ratio increases crime is by heightening thepressure on men to appear financially attractive in anincreasingly competitive marriage market.

The sex ratio is positively and significantly associated with the

propensity to commit crimes – the average sex ratio in our

sample corresponded to 34% more crime than is associated with

a naturally occurring sex ratio.

A high sex ratio is associated with greater risk-taking and

impatience, which increase the propensity to commit crimes.

However, the increases in crime are primarily driven by greater

financial pressure on men competing to find a partner in the

marriage market – the high sex ratio is associated with an

increased propensity to commit economic crimes (like drug-dealing

and theft), not violent or sexual crimes.

+61 3 9905 5438

Lisa.Cameron@monash.edu

http://users.monash.edu.au/~clisa/

@CameronLisaA

What does this mean?

What did we do?

China's "surplus" men

China's crime rate

What did we find?

How did we do it?

China's Sex Ratio and Crime: Behavioral Change or Financial Necessity?

February 2016Policy Insights, Centre for Development Economics and Sustainability, Monash University

Behavioral impacts associated with living in a society surrounded

by many more young men than women (such as greater male-to-

male competition and aggression); andIncreased marriage market competition

contributed to the rapid increase in crime in China.