The ecological fallacy and the gender ratio of suicide in China

China is the only country in which the suicide rate is higheramong women than men. We provide a demographic perspectiveon the gender differential in suicide in China. This showsthat the male/female ratio of suicide increased between 1991and 2001 and there is reason to believe this trend will continue. Among the population subgroups, only young women living inrural areas had much higher suicide rates than their male counterparts.It is argued that consideration of the gender ratio of suicidein China must take age-, gender- and region-specific suicidepatterns and the population structure into account. The increasingurbanisation of China is likely to be associated with moremale suicides and we predict that before long the male suiciderate will overtake that of females.

INTRODUCTION

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INTRODUCTION

The male/female ratio of suicide is about 4 in Western countriessuch as Australia, the USA and the UK. In Asian countries,for example India and Hong Kong (Yip et al, 2000), this ratiois often less than 2 (Mayer & Ziaian, 2002; World Health Organization, 2002).China is reportedly the only country in the world in which thesuicide rate is higher among women than men (Pritchard, 1996).This unique pattern has attracted much attention, but littleis known about its underlying causes (Yip, 1996). We suggest that a demographic perspective could shed light on the lowmale/female ratio of suicide in China. In particular, we examinewhether Chinese women in different population subgroups haveuniformly higher risk than their male counterparts, and discusshow the national male/female ratio of suicide may be affectedby the demographic changes taking place in China.

METHOD

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METHOD

We examined the gender ratio of suicides in China using themost recent mortality statistics (1991–2001) providedby China’s Ministry of Health. The Ministry’s mortalityregistry is based on a 10% sample of the Chinese population,and it is the only system in China to record causes of deathsannually for a population of 1.3 billion. In 2000 over 60% ofthe population lived in rural areas (Zhou & Ma, 2003)and the rural regions are economically deprived in comparisonwith their urban counterparts. We projected the data on suicide rates from the Ministry of Health to the age-, gender- andregion-specific population statistics of the Chinese Bureauof Statistics to adjust for the effect of the population distributionon the overall male/female ratio of suicide (for further detailsof the suicide rates and our projection method, see Yip et al, 2005a).

RESULTS

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RESULTS

We found that the male/female ratio of suicide had been increasingfrom 1991 to 2001; in 1991 the ratio was 0.78 and in 2001 itwas 0.91. The upper panel of Fig. 1 gives suicide rates byage, gender and region for China in 2001. It shows that suiciderates increased with age; a distinct peak was observed amongwomen living in rural areas in the age range 25–34 years;and rural suicide rates were higher than urban rates acrossall age-groups.

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Fig. 1 Region-, age- and gender-specific suicide rates and region-specific male/female ratios of suicide: China, 2001.

Although China’s overall male/female ratio of suicidewas still less than 1 in 2001, closer examination revealedthat this was mostly the result of the high suicide rate inone particular population subgroup, namely young women aged20–34 years living in rural areas. The Woolf test (Woolf, 1955),which is essentially a ${chi}$ ² test, was used to test the homogeneityof the male/female ratios across all age-groups for the urbanand rural populations. The values of the test statistics forassessing the homogeneity were 186.48 and 3070.10 (comparedwith a critical value of 5.226, d.f.=12) for the age-specificurban and rural gender ratios respectively. The very small probabilityvalue is in contradiction to the homogeneity assumption amongthe ratios for age-groups and region. The lower panel of Fig. 1shows the age-specific male/female ratios of suicide in urbanand rural areas: in urban areas the suicide rates among thoseunder 30 years old were slightly higher among women than men,but among the middle-aged and elderly groups the male/femaleratios were close to or larger than 1. In rural areas, womenalso did not universally have higher suicide rates across allage-groups. Male suicides were more prevalent among those over60 years old, and across the age-groups only women in ruralareas aged 20–34 years had higher suicide rates than theirmale counterparts.

DISCUSSION

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DISCUSSION

The ‘ecological fallacy’ refers to the thinkingthat what is true at the aggregate level must be true at theindividual level. One simple explanation of international differencesin suicide rates, as stated in Moksony’s compositiontheory (Moksony, 1990), is that the countries’ populationsdiffer in the proportions of those at risk of suicide. China’spopulation is still skewed towards the younger cohorts: menand women aged below 40 years accounted for 68% of the totalpopulation in 2001. Over 60% of the population lives in ruralareas (Zhou & Ma, 2003). Our results have shown that themale/female ratios of suicide were not uniform across the populationsubgroups. It was this population structure and the high suiciderates among young women in rural areas that led to a male/femaleratio of less than 1 at the national level. Such unique patternsof suicide rates and demographic characteristics must be takeninto account when interpreting the male/female ratio of suicidein China. Otherwise, it may be misleading to suggest that womenare more likely to die by suicide than men in China by referringto the low male/female ratio of suicide at the national level.

China has undergone rapid demographic changes in the past twodecades and these changes would affect the overall male/femaleratio of suicide. First, probably because of the ‘onechild’ policy which has been enforced since 1980, Chinais facing an acute problem of ageing. According to the ChineseBureau of Statistics, the total fertility rate has fallen frommore than 3 before 1980 to 1.8 in 2002, which is below thereplacement level of 2.1 (Chan et al, 2002). The proportionof the population over 65 will rise to the levels of most Westerncountries by 2025 (Hesketh & Zhu, 1997). Second, the genderimbalance at birth is now amounting to a male/female ratioof 1.15 in some districts, deviating substantially from thenorm of 1.05 (Hesketh & Zhu, 1997). The effects of the‘one child’ policy are beginning to have a severeimpact on the population distribution: the proportion in theage-group 20–39 years will shrink (Chan et al, 2002). Third, urbanisation is rapidly taking place: Zhou & Ma (2003) estimated that China’s urbanisation level rosefrom 26% to 36% between 1990 and 2000. Owing to these demographicchanges, the size of the female population in the 20–39age range living in rural areas will decline rapidly in thenext few decades. This is expected to increase the male/femaleratio of suicide at the national level, which will come toresemble more those ratios of Western countries.

What is left unanswered is how other between-country differencesmay explain the gender patterns of suicide in East and West.One such difference may lie in the availability of pesticides.Young women in most countries tend to have high rates of attemptingsuicide, but easy access to pesticide and rat poison in ruralareas of China may account for the high fatality rate. In fact,62% of suicide deaths in China resulted from ingestion of pesticideor rat poison (Phillips et al, 2002). Such easy availabilityof highly lethal substances may explain the high suicide ratesamong rural women. However, the rapid increase of charcoal-burningsuicides among middle-aged men in Hong Kong has led to a highermale/female ratio of suicide (Chan et al, 2005; Yip et al, 2005b);it remains to be seen whether the rate of suicide by charcoalburning will increase in mainland China and change the patternof suicide there. Further research is needed to explore other possible explanations, such as cultural attitudes towards genderroles, the meaning of suicide and the prevalence of mentalillness among both men and women in rural and urban communities.

REFERENCES

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