possible therefore that assumptions may vary from one country to another thereby making the country comparison not reliable or impossible.
8.9. Data on life expectancy is estimated using the UN model of quinquennial gains in life expectancy and the Philippine Life Table. Assumptions or inputs for the calculation of life expectancy or construction of the life table may be updated or revised based on the results of the Census of Population which is being conducted periodically every l0 years, although it has been conducted quinquennially twice in the past twenty years (1975 and 1995). Life expectancy for 1994 at the regional level is estimated using a straight line growth method. It is not a problem for regional or provincial HDI if there is only one source of official life expectancy data.
8.10. Aside from the Functional Literacy, Education and Mass Media Survey (FLEMMS) which is conducted every five years, simple literacy rate can also be derived from the results of the Census of Population. Adult literacy at the regional level during non-census or non-survey years is estimated by applying the logarithmic growth method on the difference between 100% and the 1980 and 1990 literacy rate. Functional literacy can be obtained from the FLEMMS. It is also a question of how the literacy is defined in each country and how it is being gathered, i.e., personal interview or actual filling-up of forms by the individuals concerned. The need for a standardized survey instrument has to be discussed for purposes of comparability between countries.
The Department of Education, Culture and Sports is the primary source of the data on the primary and secondary enrolment while the Commission on Higher Education takes care of the tertiary enrolment.
8.11. For regional HDI, the gross regional domestic product (GRDP) per capita is used. This is available at the regional level only for 1980, 1990, and 1994. GRIDP per capita is being adjusted using the Philippine GDP per capita. For the provincial HDI, income data are from the average household income from the Family Income and Expenditure Survey (FIES). The income data are being deflated using the regional Consumer Price Index (1988= 100). Incomes are also being adjusted by the Philippine average per capita income. For the HDI of the country, the real GDP per capita is being used. The GDP is converted to
