Until the late 1980s the Chinese population statistics still took pride in the good quality of the 1982 population census and one-per-thousand survey. Nonetheless, there was cumulative evidence on underreporting of births in the family planning statistics (People's Daily 1988; Su 1989; Xie 1990) and the hukou statistics (MPS & SFPC 1988). In addition, the observed abnormal sex ratio at birth in large-scale surveys, such as the 1987 sample census (Hull 1990) and the 1988 two-per-thousand survey (Johansson, Zhao and Nygren 1991), caused some authors to suspect that they may have underreported female births. Understandably, the seriousness of underreporting was not fully appreciated until the early 1990s when the 1990 census results became available.
2.1.1 Previous research on patterns and causes of underreporting
The 1990 census not only revealed underreporting of births in all statistical investigations in the 1980s, but further facilitated research about the patterns and causes of birth underreporting during the 1990s. A quick review of three main population journals in China, the Chinese Journal of Population Science, Population Research and Population and Economy, finds at least 10 papers exploring this topic specifically. The deterioration of fertility data also attracted interest from the
international demographic community (e.g. Attane and Sun 1999; Merli and Raftery 2000; Smith et al. 1997).
Most of these studies discussed the problems in the family planning statistics, while some examined problems in surveys and censuses. According to these studies, the major patterns of underreporting of births in population statistics can be summarised as follows: (1) most underreporting of births occurred in rural areas; (2) births with certain characteristics were most likely to be unreported, such as births to women under the legal minimum age at marriage, female births from daughter-only households (du nu hu), and second and higher-order out-of-plan births; (3) out-of- plan births which occurred close to the time of investigations were more likely to be unreported; and (4) previously unreported births in surveys and censuses would show up as young children in later ones (Guo 2000b; Hu 1994; Shao and Li 1993; Sun and Qing 1993; Tu and Liang 1994; Zeng 1995; Zha, Zeng and Guo 1996).
Many studies attributed the causes for underreporting of births to the family planning policy. On the one hand, the policy imposed restrictions on the number of children that each couple was allowed to bear, only one for urbanites, and at most two for peasants; on the other hand, most Chinese people, especially peasants, wanted to have more than the permitted number of children, or at least one son. To escape penalties, both local program workers and individual couples who had out-of-plan births would choose not to report of fertility behaviour accurately, as Merli and Raftery argued:
In a context in which the number of children is determined by state policy and the desire for a son is strong, neither individuals nor birth planning cadres have great incentives to report births followed by infant deaths, births not approved by the birth planning system, or female births (2000: 109).
However, this explanation did not satisfactorily answer the question why fertility data deteriorated more seriously in the 1990s, since the one-child policy had already been in effect for a decade. Therefore, many authors suggested that the program strengthening in the early 1990s should be blamed. They especially identified the introduction of the so-called ‘one-veto-down’ system (yipiao foujue) in evaluating
the performance of sub-national leaders in 1991, which stipulated that failure in family planning could wipe out performance in all other aspects. They argued that the increasing pressure offered local cadres and individual couples greater incentives for not reporting fertility behaviour accurately, which even went into collusion, because local cadres worried about the program evaluation based on the collected statistics, while couples who had out-of-plan births wanted to escape penalties (Zeng 1996). This perspective became significant at the CPA seminar targeting data quality of population statistics in 1995 (Zhang 1995), and has been widely accepted in the following years (Attane 2001; Goodkind 2004; Tan 1998; Yu and Xie 2000; Zhang 1997; Zhang and Cui 2003).
2.1.2 Limitations and problems in previous research
While previous research enriched the general understanding of the deterioration in data quality, there are also many limitations and problems in identifying the causes of underreporting in the 1990s. First, when many authors concluded that all population statistics had suffered from more serious underreporting of births since the early 1990s, they neglected the differences in the completeness of birth records between different data sources (e.g. Goodkind 2004; Merli and Raftery 2000; Tan 1998). These differences were nothing new even in the 1980s. It was found, for example, that ‘in the 1980s and 1990, the surveys and censuses have consistently demonstrated far more complete birth reporting and far more complete counts of young children than the registration system’ (Banister 1994: 257). During the 1990s, these kinds of differences continued. For example, in the widely cited paper of Zeng (1996: 32), he listed the huge difference between births recorded in the family planning statistics and those estimated from the 1992 survey in 1991-92, which unfortunately did not attract much attention. A more recent study shows the hugely different number of births between those recorded in the family planning statistics and hukou statistics and those estimated from annual surveys during the past two decades (Scharping 2003: 250).
Second, given the vast discrepancies across data sources, one would have to suggest factors affecting data quality other than the family planning program. Many authors
too simply attributed underreporting of births to the family planning program, especially the program strengthening since the early 1990s. As mentioned in Chapter 1, this was not a complete understanding because of its neglect of the effects the program strengthening in the 1990s on fertility reduction. Moreover, if the program strengthening were the only cause for underreporting, logically all statistics should have reported the same fertility figures at the same time. The reason for ensuing this agreement between all sources is very simple but reasonable. Because of the availability of several sources of statistics, the higher-level family planning administrations certainly could have used other sources to evaluate program performance at the lower levels if they did not trust one set of statistics. This was the practise of the SFPC in the 1990s, which shifted to the SSB annual surveys to evaluate the program performance. Thus, if there were systematic engineering by local cadres and individual couples, they must have considered every possibility and taken everything into account. However, this was not the case (Zhang and Yuan 2004). Obviously, ignorance of the difference between each data source resulted in incomplete understanding of causes for underreporting of births.
Third, it has not been recognised that the difference between data-gathering agencies, and the different degrees of involvement of program workers and individual couples in statistical investigations, can make a difference in data quality. For example, whether the data-gathering agency is the family planning administrations or other agencies, or whether local program workers are involved in data collection, or whether information is gathered directly from individual respondents, or whether interviewers are experienced statisticians or adequately trained, could all affect the completeness of births in each investigation. Many studies claimed that both local program workers and individual couples contributed to underreporting of births (see Attane 2001; Merli and Raftery 2000; Tan 1998). However, for the data gathered by other than the family planning administrations, the data collectors are not program workers and may have different considerations. In addition, even if both local program workers and individual couples are involved, there have different considerations: the former are concerned with whether they can meet the pre- assigned family planning targets and will resort to data manipulation if necessary, while the latter care more about whether they can achieve their fertility goals both in family size and in sex composition. As mentioned earlier, only local program
workers are involved in the family planning statistics, but individual couples are the primary information providers in surveys and censuses.
In general, it is mistaken to conclude that births would be equally underreported in different data sources, and it is too simple to attribute underreporting to the effects of the family planning program. In addition, there was a lack of complete and correct understanding of the 1991 Decision and the following strengthening of program efforts. Moreover, It is very important to recognise that who collects the fertility data or how the data are collected also strongly affect the quality of each data source.