About the data
Definitions
Data sources
School enrollment data are important indicators of the size and capacity of the education system and may be useful measures of outcomes, but they are notoriously rife with errors. The data here are reported to the United Nations Educational, Scientific, and Cultural Organization (UNESCO) by national education authorities on the basis of annual enrollment surveys, typically conducted at the beginning of the school year. They do not reflect actual rates of attendance or the nonattendance of dropouts during the school year. Furthermore, school administrators may have incentives to exaggerate enrollments. Behrman and Rosenzweig (1994), comparing official school enrollment data for Malaysia in 1988 with gross school attendance rates from a household survey, found that the official statistics systematically overstated enrollment.
Overage or underage enrollments may occur, particularly when parents prefer for cultural or economic reasons to have children start school at other than the official age. Children's age at enrollment may also be inaccurately estimated or misstated, especially in communities where registration of births is not strictly enforced. Parents who choose to enroll their underage children in primary school may do so by over-reporting the age of the child. And in education systems where the authorities are willing to alter school records, ages for children repeating a grade may be deliberately underreported.
Other problems affecting cross-country comparisons of enrollment data stem from measurement errors in estimates of school-age populations. Age-sex structures from censuses or vital registration systems, the primary sources for school-age population data, are commonly subject to underenumeration (especially of young children) in order to circumvent laws or regulations or from age heaping resulting from parents' rounding up children's ages. While adjustments for age bias are commonly made in census data, such adjustments are rarely made for data from inadequate vital registration systems. Compounding these problems, pre- and post-census year estimates of school-age children are either interpolations or projections (see the discussion of demographic data in the notes to table 2.1).
In using enrollment data, it is important to consider repetition rates, which are quite high in some developing countries, leading to a substantial number of overage children enrolled in each grade. The gross enrollment ratios here provide an indication of the capacity of each level of education relative to the age group that should be enrolled at that level. But a high ratio does not necessarily indicate a successful education system. The quality of schools varies widely within countries, between countries, and over time. Thus a lower enrollment ratio could be consistent with greater aggregate, quality-adjusted educational capital if quality more than compensates for quantity.
The gross enrollment ratios for primary and secondary levels have been calculated by taking into account different national systems of education with different durations of schooling at the primary and secondary levels. For the tertiary level the ratios are expressed as a percentage of the population in the five-year age group following the secondary school leaving age. The population estimates used to calculate gross enrollment ratios are from the United Nations and are midyear estimates, while enrollments refer to the beginning of the school year.
The age efficiency ratio, a useful complement to the gross enrollment ratio, reflects the extent to which planned (net) enrollments match actual (gross) enrollments. It does not measure the cost-efficiency of the system. Nor does it reflect the quality of the education provided. However, lower efficiency ratios are likely to be associated with higher direct costs of schooling because of the cost of providing teachers, materials, and classrooms for repeaters, and with higher opportunity costs of providing schooling to overage students. Windham (1988) provides a general discussion of efficiency indicators.
In general, the enrollment data in this table cover both public and private schools but may exclude certain specialized schools and training programs. Interested readers should consult the notes to the appropriate tables in UNESCO's Statistical Yearbook 1995.
Table 2.8a Social and private rates of return to investment in education, by level of schooling
percent
|
|
|
Social |
|
|
Private Secondary |
|
|
19.9 |
13.3 |
11.7 |
39.0 |
18.9 |
19.9 |
|
15.5 |
11.2 |
10.6 |
17.4 |
15.9 |
21.7 |
|
17.9 |
12.8 |
12.3 |
26.2 |
16.8 |
19.7 |
|
24.3 |
18.2 |
11.2 |
41.3 |
22.6 |
27.8 |
|
.. |
10.2 |
8.7 |
.. |
12.4 |
12.3 |
Source: World Bank 1995d.
• Gross enrollment ratio is the ratio of total enrollment, regardless of age, to the population of the age group that officially corresponds to the level of education shown. Estimates are based on UNESCO's classification of education levels, as follows: Preprimary provides education for children not old enough to enter school at the first level. Primary, or first level, provides the basic elements of education at elementary or primary school (see table 2.7 for duration of primary school). Secondary provides general or specialized instruction at middle, secondary, or high schools, teacher training schools, and vocational or technical schools; this level of education is based on at least four years of instruction at the first level. Tertiary requires, as a minimum condition of admission, the successful completion of education at the second level or evidence of attainment of an equivalent level of knowledge and is provided at a university, teachers college, or higher-level professional school.
• Age efficiency ratio is the ratio of net enrollment to gross enrollment at the primary and secondary levels.
• Net enrollment ratio is the ratio of the number of children of official school age enrolled in school to the number of children of official school age in the population.
Gross enrollment ratios are from UNESCO's Statistical Yearbook 1995. Age efficiency ratios were compiled by World Bank staff using the UNESCO database on enrollment by level, age, and gender.