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China's Excess Males, Sex Selective Abortion, and One Child Policy: Analysis of Data from 2005 National Intercensus Survey Author(s): Wei Xing Zhu, Li Lu, Therese Hesketh, Liu and Zhang Source: BMJ: British Medical Journal, Vol. 338, No. 7700 (Apr. 18, 2009), pp. 920-923 Published by: BMJ Stable URL: http://www.jstor.org/stable/20512658 Accessed: 21-10-2016 01:37 UTC

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Open Access: free full text available online For the full versions of these articles see bmj.com

China's excess males, sex selective abortion, and one child policy: analysis of data from 2005 national intercensus survey Wei Xing Zhu,1 Li Lu,2 Therese Hesketh3

EDITORIAL by Uu and Zhang

'College of Law, Political Science and Public Administration, Zhejiang Normal University, linhua, Zhejiang 310347, China

2Institute of Social and Family Medicine, Zhejiang University, Hangzhou 310016, China

3Centre for International Health and Development, University College London, London WC1N 1EH Correspondence to: T Hesketh [email protected]

Cite this as: BMJ 2009;338:b1211 doi:10.1136/bmj.b1211

This article is an abridged version of a paper that was published on bmj.com. Cite this article as: BMJ 2009;338:bl2 11

ABSTRACT Objectives To elucidate current trends and geographical

patterns in the sex ratio at birth and in the population

aged under 20 in China and to determine the roles played

by sex selective abortion and the one child policy.

Design Analysis of household based cross sectional

population survey done in November 2005.

Setting All of China's 2861 counties.

Population 1% of the total population, selected to be broadly representative of the total.

Main outcome measure Sex ratio defined as males per 100 females. Results 4764512 people under the age of 20 were included. Overall sex ratios were high across all age

groups and residency types, but they were highest in the

1-4 years age group, peaking at 126 (95% confidence interval 125 to 126) in rural areas. Six provinces had sex

ratios of over 130 in the 1-4 age group. The sex ratio at

birth was close to normal for first order births but rose

steeply for second order births, especially in rural areas,

where it reached 146 (143 to 149). Nine provinces had ratios of over 160 for second order births. The highest sex

ratios were seen in provinces that allow rural inhabitants

a second child if the first is a girl. Sex selective abortion

accounts for almost all the excess males. One particular variant of the one child policy, which allows a second

child if the first is a girl, leads to the highest sex ratios.

Conclusions In 2005 males under the age of 20 exceeded females by more than 32 million in China, and more than

1.1 million excess births of boys occurred. China will see

very high and steadily worsening sex ratios in the

reproductive age group over the next two decades.

Enforcing the existing ban on sex selective abortion could

lead to normalisation of the ratios.

INTRODUCTION In the absence of intervention, the sex ratio at birth is consistent across populations at between 103 and 107 boys born for every 100 girls.'2 Higher early mortal ity among boys ensures a ratio of close to 100 in the reproductive years. However, in many countries, mainly in South and East Asia, the sex ratio deviates from this norm because of the tradition of preference

for sons.' Historically, preference for sons has been manifest postnatally through female infanticide and the neglect and abandonment of girls.4 However, since the early 1980s selection for males prenatally with ultrasonographic sex determination and sex selective abortion has been possible. The highest sex ratios are seen in countries with a combination of preference for sons, easy access to sex selective technology, and a low fertility rate.' In the era of the one child policy the fact that the problem of excess males in China seems to outstrip that of all other countries is perhaps no surprise.'

Some of the evidence for this sex imbalance in China has been challenged, because accurate population based figures have been difficult to obtain.8' Births classified as "illegal," violating the one child policy, may be concealed to avoid penalties. ""' Under-report ing of births of girls may be more common in this context.'2"' However, if girls are not reported at birth, they are likely to filter into the statistics later, as registration is necessary for immunisation or to start school. '4 Therefore, examining the sex ratio across dif ferent age bands provides a more accurate picture.

The objectives of this study were to elucidate current trends and geographical patterns in the sex ratio at birth and in the population under the age of 20 in China and to explore the role played by sex selective abortion and the one child policy in the sex imbalance.

METHODS

We analysed data from the intercensus survey of 2005,

which was carried out on a representative 1% of the

total population in November 2005. The survey cov ered all of China's 2861 counties. Only data for the under 20 age group are reported here.

The major outcome variable is the sex ratio, defined

as males per 100 females. We calculated the excess of

males for all age groups by using an average of the mean sex ratios from 13 countries that have normal

secondary sex ratios and little or no sex preference.'=

These were 105 for the 1-9 age group and 104 for the

10-19 age group.

920 BMJ 1 18 APRIL 2009 I VOLUME 338

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Table 1 1 Sex ratio (95% confidence interval) by age and residence, under 20 year olds

Age (year of birth)

<1 year (2004-5) 1-4 years (2000-4) 5-9 years (1995-9) 10-14 years (1990- 15-19 years (1985 Residence No (%/6) (n=182 393) (n=724 709) (n=1 060 664) 4) (n=1 353 263) 9) (n=1 443 483) All 4 764 512 119 (119 to 120) 124 (123 to 124) 119 (119 to 120) 114 (113 to 114) 108 (108 to 109)

Urban* 1 073 229 (23) 114 (112 to 115) 116 (115 to 117) 116 (115 to 117) 112 (111 to 114) 101 (100 to 103) - - - - - ........... ....................................................................... ............................ .. ............... .......................... ................. ..................................... ....- _ - - - --............................... ............................................................................ - -

Townt 813 386 (17) 117 (115 to 119) 122 (120 to 124) 121 (120 to 122) 116 (115 to 117) 109 (107 to 111)

Ruralt 2 877 897 (60) 122 (121 to 122) 126 (125 to 126) 120 (120 to 121) 114 (113 to 114) 111 (110 to 111) *Area with more than 100 000 non-agricultural population.

tPopulation of at least 20 000, where non-agricultural population exceeds 10%. tMore than 90% agricultural workers.

The survey counted 4 764 512 people under the age of 20: 1 073 229 (22%) urban residents, 813 386 (17%)

town residents, and 2 877 897 (60%) rural inhabi tants. In the 12 months before the study 161 109 births were reported: 23% in urban areas, 17% in towns, and 60% in rural areas. First order births accounted for 63% of the total, second order for 32%, third order for 4.3%, and fourth or higher order for 1%.

Under 20 sex ratio

Table 1 shows the sex ratio by age group and type of residency. Sex ratios were consistently higher than normal across residency type and all age groups except

for urban 15-19 year olds. Sex ratios peaked in the 1-4

age group; the highest was 126 (95% confidence inter

val 125 to 126) in rural areas. Table 2 shows the sex ratio by age group for all provinces. Only two pro vinces, Tibet and Xinjiang, had sex ratios within nor

mal limits across the age range. Two provinces,Jiangxi

and Henan, had ratios of over 140 in the 1-4 age group;

four provinces Anhui, Guangdong, Hunan, and Hai nan had ratios of over 130; and seven provinces had ratios between 120 and 129. The provinces with the highest sex ratios are clustered together in the central

southern region. The excess of males increased from 5.10% (n=142 634) in the cohortborn between 1986 and

1995 to 9.4% (n=184 970) in the cohort born between 1996 and 2005 across the whole country.

Sex ratio at birth

The total sex ratio at birth for the 12 months to October

2005 was 120 (119 to 121) for the whole sample (see bmj.com), with a gradient between urban (115, 113 to 117),town (120, 118to 122), andrural (123, 121to 124) areas. This equates to 11 320 excess boys born for the

year for the whole sample. These overall figures con ceal dramatic differences in sex ratio at birth by birth

order. The sex ratio at birth for first order births was

slightly high in cities and towns but was within normal

limits in rural areas. However, the ratio rose very stee

ply for second and higher order births in cities 138 (132

to 144), towns 137 (131 to 143), and rural areas 146 (143 to 149), although the numbers of second order births in cities were low. For third births, the sex ratio

rose to over 200 in four provinces, although third births accounted for only 4.3% of the total.

DISCUSSION

The findings paint a discouraging picture of very high

and increasing sex ratios in the reproductive age group

in China for the next two decades. The sex ratio increased steadily from 108 in the cohort born between

1985 and 1989 to 124 in the 2000 to 2004 cohort. How

ever, the ratio then declined to 119 for the 2005 cohort,

perhaps indicating the beginning of a reduction in sex

ratios for the future. Sex ratios were outside the normal

range for almost all age groups in almost all provinces.

The sex ratios rose dramatically between first and sec

ond order births, with very high sex ratios for the very

few higher order births. The highest ratios were seen in

the centre and south of the country. Extrapolating from

this 1% sample to the whole country, we estimate that

an excess of 1 132000 boys were born in the 12 months

to October 2005 and that an excess of 32 706 400 males

under the age of 20 existed in the whole of China at that

time, 18497000 of them under the age of 10.

This is the most recent nationwide demographic sur

vey in China. A large survey aiming to represent 1% of

the total population obviously has some limitations.

Complete coverage of households and inhabitants is impossible on such a large scale. Furthermore, extra

polation to the whole population from a 1% sample should be done with caution. The small sample size at provincial level in some age bands and for second and

higher order births leads to wide confidence intervals,

illustrating the uncertainty around these figures. How

ever, the overall credibility of the data is increased by

the high sex ratios in older age groups, for which con

cealment and under-reporting of girls would be diffi

cult, and by the number of births counted for the 12 months to October 2005 (161 109), which matches the estimate of 16 million births a year from other sources. 16

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Table 2 1 Sex ratios (95% confidence intervals) by age group and province, and excess males

Region and Age group Excess Excess province...... .......... ..............m ales............. - - ....m ales.......... m te a e

(population in <10 years 10-20 millions) No <1 year 1-4 years 5-9 years 10-14 years 15-19 years (%) years (%/) All 4764512 119(119tol20) 124(123tol24) 119(119tol20) 114(114toll5) 108(107tol08) 9.4 5.1 North:

Beijing (14) 3 5657 114 (102 to 127) 112 (105 to 118) 11O (106 to I15) 104 (lOOtolO09) 111 (108 to 1 15) 5.4 4.1

Tianjin (10) 29 170 114(100tol30) 118(111to126) 115(109tol22) 110(106toll5) 99 (96 to 103) 7.5 1.7 Hebei (65) 250 933 120(116tol25) 122(120tol25) 115(113toll7) 111(109toll3) 104(102tol05) 8.4 3.2 Shanxi (32) 131 763 116(110tol23) 112(109toll6) 109(107tolll) 109(107tolll) 106(104tol08) 5.1 3.6 Inner 76 693 114(107tol22) 107(103tolll) 109(106toll3) 110(107toll3) 107(104tol09) 4.3 4.0

Mongolia (23)

Northeast:

Liaoning(42) 118 018 113(106tol20) 114(111to117) 111(108toll4) 110(108toll3) 106(103tol08) 5.6 3.7 Jili (26) 81 133 113 (105to 121) 112 (108to 116) 113 (IlO to 117 110 (107to 113) 107 (104to 109) 5.9 3.8

Heilongjiang 112 057 109(103toll6) 111(108toll5) 107(104toll0) 108(105toll0) 107(105tol09) 4.1 3.4 (38) East:

Shanghai 37 406 117(106tol28) 109(103toll5) 111(105toll6) 108(103toll3) 98 (95 to 101) 4.9 0.4 (17)

Jiangsu (71)_ 230 997 125 (120to 131) 123 (120to 126) 121 (119to 124) 118 (116to 120) 105 (103 to 106) 10 5.0

Zhejiang 1 50 125 114(109toll9) 113(l11to116) 113(111to116) 113(111to116) 108(106tollO) 6.3 5.0 (43) Anhui (61) 256 350 131(126tol37) 138(135tol4l) 124(122tol27) 115(114to117) 107(106tol09) 12.9 5.5 Fujian (33) 129 146 122 (116to 129)__119 (116to 122) 124 (121 to 127) 118 (116to 121) 101 (99 to 103) 9.8 4.2

Jiangxi (41) 186 198 129(121tol37) 143(140tol46) 130(128tol33) 118(116tol20) 114(112toll6) 14.8 7.6 Shandong 303 287 114(110toll8) 116(114toll8) 116(114toll8) 115(114toll7) 106(105tol08) 7.4 4.5

(9 1 ) -__ _ _-----__ _ _ _ _ _ Central:

Henan(95) 386 594 122(118tol26) 142(140tol44) 131(129tol33) 119(118tol2l) 110(109tolll) 14.4 6.7 Hubei (58) 208 230 128(122tol35) 129(126tol33) 129(126tol32) 120(118tol2l) 118(117tol20) 12.6 8.7 Hunan(64) 232 938 122(117tol27) 133(130tol36) 122(120tol24) 115(113toll7) 112(110toll3) 11.6 6.1 Guangdong 384 845 119(115tol23) 133(131tol35) 127(126tol29) 115(113toll6) 96 (95 to 97) 12.3 2.2

(70) __ Guangxi (46) 199 776 121(116to126) 122(120tol25) 127(125tol30) 122(120tol24) 123(121tol25) 11.0 10.2 Hainan (7.5) 36 427 123 (111 to 136) 134 (127to 141) 135 (129 to141) 120 (113 to 127) 123 (118to 128) 6..2 9.3

Southwest:

Chongqing 100 070 112(104tol20) 119(115tol23) 117(114tol20) 113(110toll5) 114(111to117) 7.9 6.2 (31)

Sichuan (84) 311 530 115(110toll9) 116(114toll8) 114(112toll6) 111(110toll3) 108(106tol09) 6.8 4.6 Guizhou (37) 178 547 128(112tol34) 127(124tol30) 115(113toll7) 112(110toll4) 119(117tol22) 9.0 7.2 Yunnan(41) 189 774 113(108toll8) 115(113toll7) 112(110toll4) 112(110toll4) 112(110toll4) 6.2 5.9 Tibet (3) 13 764 102 (88 to 120) 104 (96 tol113) 105 (98 to 112) 102 (95 to 108) 105 (98 to 112) 2.1 1.6

Northwest:

Shaanxi (36) 141 904 134(126tol43) 125(121tol29) 123(120tol26)' 117(115toll9) 112(110toll4) 10.9 6.6 Gansu(25) 112 399 116(109tol24) 120(117tol24) 116(113toll9) 109(107tolll) 106(104tol09) 3.8 0.1 Qinghai (5) 23 483 117(103tol33) 111(105toll8) 109(104toll5) 104(98toll0) 100 (95 to 106) 5.0 0.1

Role of sex selective abortion

The precise role of sex selective abortion in the sex imbalance has been unclear, not least because the practice is illegal in China and obtaining reliable fig

ures is difficult. If under-registration of girls

accounted for most of the excess births of boys, then sex ratios would fall from birth through early childhood, as girls are required to be registered for immunisation and school entry.'4 Our finding that the sex ratios for the 1-4 year old cohort are higher

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WHAT IS ALREADY KNOWN ON THIS TOPIC

The reported sex ratio (males per 100 females) in China is high, but accurate population based figures for actual sex ratios have been notoriously difficult to obtain

The role of sex selective abortion and the influence of the one child policy on the sex imbalance have been unclear

WHAT THIS STUDY ADDS

China will see very high and steadily worsening sex ratios in the reproductive age group for the next two decades

Sex selective abortion accounts for almost all the excess males

One particular variant of the one child policy leads to the highest sex ratios

than those at birth and in infancy tends to refute this

hypothesis. Comparison between each cohort speci fic sex ratio and the corresponding sex ratio at birth

from previous census data also lends support to the

assertion that under-registration of girls is not a major

contributor to high sex ratios at birth.'7 8 Infanticide

is another possible explanation for girls missing at

birth, but is widely acknowledged to be very rare now. "9-22

The dramatic increase in sex ratio with second births

shows that couples are selecting to ensure a boy, the so

called "at least one son practice.""' In urban areas where few couples are allowed a second child, the high sex ratio for first order births suggests some sex

selection occurring with the only child. Finally, the steady rise in sex ratios across the birth cohorts since

1986 mirrors the increasing availability of ultrasono graphy over that period.'

Role of one child policy

The relation between the sex ratio and the one child

policy is a complex one. The policy is implemented differently across the country (see bmj.com), and our

data suggest that the sex ratio is related to the way in

which the policy is implemented.'4 Whereas in most

cities only one child is allowed, three main variants of

the policy exist in rural areas. Our data show that the

type 2 variant, which allows couples a second child after a girl, results in the highest sex ratios for second

order births and the overall highest sex ratios.

Medium sex ratios were most common in the strict

type 1 provinces where 40f/o of couples are allowed a

second child but generally only if the first is a girl.

However, these provinces are also wealthier, levels of education are higher, and traditional values of pre

ference for sons are changing.2' The lowest ratios are seen in the type 3, most permissive, provinces. How

ever, these provinces are sparsely populated and

poor, inhabited partly by ethnic groups who are gen erally less inclined to prefer sons and less accepting of abortion.:t

The policy implications are clear. Changing the reg ulations in force in type 2 provinces, which permit most couples a second child after a female birth, could help to reduce the sex ratio.

Contributors: All the authors participated in the analysis and in preparing

the tables and saw and approved the final version of the paper. ZWX is

the guarantor.

Funding This study was funded through a China-UK excellence

fellowship for TH from the Department of Innovation, Universities and

Skills. Competing interests: None declared.

Ethical approval: Not needed.

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Accepted: 27 November 2008

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