Determinaciones fenoménicas de la vida

2.5.1 Cases Studies

2.5.1.1 Example 1: The reliability of Lesotho’s census data (1986 and 1996 censuses)

Mba, (2003) assesses the reliability of 1986 and 1996 censuses of Lesotho. The main purpose is to assess the quality of age and sex distribution reported. He uses Whipple’s index Myers index and Bachi’s index. He finds that the preference of even numbers occurred in the census of Lesotho. The Whipple’s index of 1986 is 115; it decreases to 106 in 1996. Myers index also declines from 11 in 1986 to 9 in 1996 and, Bachi’s index in the same vein decreases from 7 to 6.

However, there is an improvement in the quality of its data. This study presents some inconsistencies in the reported age and sex distribution of Lesotho. In regard to single year age distribution, there is evidence of distortions in reporting age. The patterns of digit preference occur in both censuses of Lesotho. In 1986 census, digit 0 is most preferred by males and females follow by 8, 6 and 2. In 1996 the digit 6 is most preferred by males and females preferred the digit 0 more than anyone. Both sexes prefer digit 0, follow by digit 6. The magnitude of preference and avoidance in Lesotho is very small when compared to African standards. The sex ratios are fluctuating in both the 1986 and 1996 censuses. The age group 35-39 with sex ratio of 102 in 1986 and the sex ratio of 105 at the age group 45-49 presents inconsistencies in the age data. In the same vein, having 103 of sex ratio at the age group of 45-49 in 1996 while preceding age group has lower sex ratio demonstrates deficiencies in the data.

However, the two censuses indicate that the number of females is greater than that of males. Mba (2003) assumes that the low sex ratio over the decade may result in under reporting of females, high emigration of males, low sex ratio at birth and high male mortality at subsequent ages. In some case after working in South Africa, males migrate back into Lesotho, this for retirement

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purpose. The derived age ratios and the age accuracy affect probably at the age group 45 and over. The distortion observed in 1986 census data indicates that there is over enumeration at the age groups 5-9, 10-14, 50-54, and 65-69 for both sexes while other age groups register under enumeration.

In 1996, the highest over enumeration is observed at age groups 60-64 for both sexes, while the highest under enumeration occurs at age group 65-69 for both sexes. These findings indicate that old ages are more likely to state their ages incorrectly than young ages. This issue links to poor level of education of old ages. Considering the Age-sex accuracy index, a slight improvement occurs during the study period. In 1986, the index is 35 and in 1996 it is 32. Despite the fact that the data quality is not accurate, these results are significantly lower than what obtains in many Sub-Saharan countries. The study reveals that the reported age sex distribution of Lesotho’s population suffers from inconsistencies but the exact degree of errors cannot be determined because of complexities in the patterns of these errors. Civil registration systems are still developing in Lesotho, it is impossible to determine the correct age distribution in Lesotho without appropriate birth certificates even when migration is considered.

2.5.1.2. Example 2: Estimating Adult Mortality in Cameroon from Census Data on Household Deaths: 1976-1987

Bangha (2008) assesses the age and sex distribution data of child and adult mortality using 1976 and 1987 censuses data of Cameroon. The percentage distribution of single year for both censuses presents a general decline as age advances with some patterns of strong preference for digits 0 and 5 in the reporting of ages. In regard to 1976 census, the patterns of preference decrease in 1987. The heaping declines with the processing of grouping age. When comparing 5-years and 10-5-years in parallel lines, there is no crossover to find inter-censal migration movement or a large under enumeration in one census relative to other. The age specific sex ratios are consistent indicating more male than female births.

The sex ratio estimates at 96 per 100 for 1976 and 1987 with a constant fraction of males of the total population. The sex ratios by age groups vary from 104 for the youngest age group from

0-       

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14, to below 100 for age groups 15 and above. The patterns of age specific sex ratios are consistent with the whole picture for Africa (UN, 2004) where the sex ratios are around 100 for the age group 0-14, decrease to 90 for the broad age group 15-59, and then drop below 80. The overall sex ratio of household deaths reported for the 12 months preceding the 1987 census is 117 males per 100 females which is close to 116 reported for the 12 months prior to the 1976 census. The observed age specific patterns reveal an excess male mortality.

The sex ratios of reported deaths by age group start at 120 and remain above 100 across age except for ages 15-44 where the male mortality drop consistently and reappear at the end of the reproductive span (45-49). The pattern is the same for the two censuses, except the one observed between ages 15-49 which is deeper for the first census than for the second. This illustrates high maternal mortality at the first census which declines by the 1987 census. The young adults and old adults are generally missing during a census enumeration. In this study, the migration age selectivity is not referring for males since this pattern is observable for both sexes; the missing can be a potential shifting of individuals as a result of misstatement.

The 1976 census is more complete compared to the 1987. The statistics show that the 1987 is about 93 per cent complete relative to the 1976 census, with the male enumeration estimates at 95 per cent complete and females at 90 per cent complete. The under enumeration is largely experiencing for the second than the first census. The population is experiencing decline adult mortality between 1970 and 1980. The results decrease by sex showing that the adult’s female mortality is improving over the inter-censal period. The influence of various factors (socio-political, economic and environmental) occurred in Cameroon during 1980, has disturbing and producing the negative effect on the health of adult males. These difficulties may have inducing a differential male-female mortality response. However, the third enumeration round in 2005 would help to evaluate this study once its data will be available.

2.5.1.3. Example 3: Investigation Pattern of Preference in the Census Data (1994-2009), 2.5.1.3.1 Philippines 1990

Rodriguez (2009) assessed the reliability of the age distribution of the Philippines in 1990 from ages 0 to 99 which appears in Siegel & Swanson (2004), p. 103. The distortions seem to

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represent some form of age misreporting. The researcher investigates pattern of preference and obtains strong preference for 0, and some for 1, 2 and 5 while strong avoidance appears for 8, 9 and 6. Philippines, as many developing countries, is facing problem of registration of births and is also observing high rate of mortality. Considering the findings, the expected people should be more at age 0 than 5 or 9, and more at 10 than 15 or 19 and so forth. Using Myers method, Rodriguez (2009) found that with data cover the range 10-89, Myers’s blended index was 1.93.

According to this result there is a need to reclassify 2 per cent of the cases to have uniform distribution. Rodriguez (2009) continues to sum all the range 10 to 99 (excluding 100 and above, which is left out of the dataset which means that the assumption of having all frequencies above 99 are all 0); applying that assumption, the Myers’s blended index becomes 2.33. The preference is most pronounced at age 0, 5 and 9 while avoidance is more observed at age 3, 6 and 1. The problem of education could be another possible reason affecting this population of Philippines to not report properly their ages.

2.5.1.3.2 Breastfeeding Duration: Bangladesh 1975-1976

Rodriguez (2009) studied the duration of breastfeeding in the last closed interval between the next to last and last child from Bangladesh. He found that the duration of breastfeeding was related with the age of mother. He also identified that preference for multiples of a year and multiple of 6 months are closed and common to wishes of women. Generally women tend to wean the child at age one, two or three. Using the month’s option, it could extent to 60 months, an exact multiple of 12, and put down 11 more months of data for blending. Rodriguez (2009) found the Myers index with a range of 0 to 59, he observed 63 per cent of the cases report an exact multiple of 12 months (equal to a year) and 25 per cent report a multiple of 6 months (but not 12). Myers blended index was equal to 70.58 indicating the pattern of preference was more pronounced in this population. The quality of distribution was totally inaccurate. There was a great need to reclassify 71 per cent of the cases to obtain a uniform distribution by month. The value of Myer’s index (70.58) was considered very high compared to the full range of this index which varies from 0 to 59. This index confirms that the reporting of the duration of breastfeeding in the population of Bangladesh is significant. A possible reason explaining why respondents often report wrong their duration of breastfeeding with multiple of 12 might be that the children born in rural areas were breastfed for shorter periods than those born in urban areas of

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Bangladesh. Also, the duration of breastfeeding decreases systematically according to the level of education of the mother despite the fact that she tends to declare inaccurate responses.

2.5.2 Progress Made in the Methodologies

Many aspects of individual life, public policy, ranging from schooling, health care, and social security to labour force participation and productivity relate to age and gender showing the matter of great interest. The collection of data on age and sex distribution from censuses or surveys presents serious difficulties which affect the quality of these data in many developing countries. Age is an important demographic characteristic with an impact on the dynamic of the

whole aspect of the size of the population under study. The completeness and the accuracy of reporting the age or the date of birth are very critical issues. The additional question

on date of birth, the birth history, and the important events occurred in the past and the characteristics of other members in the household contribute to achieve the approximate age of those respondents unable to provide their exact age. The evaluation of these data require a consensus about methods, content of censuses or surveys, civil registration systems, sampling procedures and training procedures to produce valuable data. Literacy of population is showing a positive expectation.

Nowadays, South African government is paying attention to the vulgarization of vital registration systems and they are also providing good awareness to its populations. There is a slight improvement, but in many of Sub-Saharan countries, the lack of progress towards a complete civil registration system remains critical. According to the age heaping in Africa, there is no change occurring. The mobility of population is an obstacle to the improvement of these data.

For instance, the emigration of well-educated Whites, productive and skilled workers highlights the sluggish economic growth in South Africa. There is a need of influx of skilled workers to fill this gap. Huge efforts also are needed in translation of instruments into local languages implying extensive gains in the accuracy of responses and possibly reducing` the incidence of interviewer error. Another issue which arises in this study is that after age 40, the rate of male mortality is significantly higher than for female which reveals female lives longer in retirement years. Their less participation in Labour Force and the quality of their work cannot help them to afford the family needs.

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In many African countries, the availability of data on age and sex distribution is published with delays in the UN Demographic Yearbook. For example, the data on family and household of Morocco resulted in long delays 1975-1992 (New York, the population council, 1992) as cited (Cleland, 1996). Greater funds are available for data collection but during the analysis process the agents involve in this operation always facing problem of funding. These days, Statistics SA are given more attention in the training for enumerators and supervisors in such a way to improve their effectiveness on the field during October 2011 (census).

UN recommendations are aware of the particular problems of recall that might arise in time specific questions in African censuses. The variations in age and sex distribution occur as result of differential mis-enumeration. The problem of age misreporting is particularly serious in Africa and may be compounded by different patterns of misreporting for males and females. Age and sex help to evaluate the importance one should assign to explicit consideration of such other dimensions as labour force, region, educational status, health facilities…

Disparities in data on age and sex persist. The continued assessment of age is essential. No country follows international recommendations to the letter; many national statistical agencies respect only the basic concepts. As a result, the scientific quality of enumerations improves spatial comparability increases (UN, 1998). The population census becomes a global phenomenon, the making of data samples; harmonization of census is an obvious way of enhancing the use of these data. Each year brings more relevant data by which these analyses can be made more accurate. Post-censal field checks are increasing. It is now possible to evaluate the data much better and to use them more effectively despite their deficiencies. However, two important challenges remain to deal with, first, the problem of unbalance sex-ratio in developing countries with its implications when the excess of females are adults and second, the growing number of extreme-age with its implications in the future policies of these countries.

In conclusion, despite the systematic checking in all steps (procedures) during the census, the researcher has to examine all difficulties encountered during the fieldwork. In this case, a post enumeration survey is recommended to assess the quality of data collected. The extent to which they provide an adequate indication of patterns of population census gives the possibilities for limitation of their use in population analysis. The next chapter deals with methods applied in the research.

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CHAPTER THREE

METHODOLOGY 3.1 Introduction

This chapter discusses the key methods applied in this study, the ways in which information utilized were acquired and methods of analysis. In particular, it emphasizes the techniques used for data collection; sampling design, variables and procedures. The instruments employed were Census 2001, General Household Surveys (2004 and 2007), Labour Force Surveys (2005 and 2007) and Community Survey (2007). The chapter highlights how data were analyzed, using indirect methods such as Whipple’s index, Myer’s index, CIUN, age ratios, sex ratios and population pyramids to evaluate the quality of declaration on age and sex. The procedure involves the comparison of statistics for each instrument, by type at national, provincial or per population groups and also for the same instrument over years for different instruments over years. The chapter ends with the discussion on the limitation of this study.