_Gender Equality and Economic Development: The Role for ICTs_ 17 aged 15 years or older for many countries spanning the period 1960 to 2000 on a 5-yearly basis. There are 142 countries with at least one observation and 107 countries with complete information. The second global data set for average years of schooling is that of Cohen and Soto (2001)<sup>13</sup> , which covers 95 countries and spans the period 1960 to 2000 on a decade basis. In order to obtain the broadest coverage of countries for data on educational attainment, we combined the information from Barro-Lee and Cohen-Soto data sets to obtain the resultant data set that covers 144 countries for the period 1960 to 2000. If educational attainment data on a specific country is contained in both data sets, then the simple average of two data values were taken to obtain the final measure of the average years of schooling.

In view of the fact that the education level of the population tends to change very slowly and to enable the maximum number of observations to be included in the regression samples, a linear interpolation procedure was employed to fill in missing observations. This resulted in many countries have annual observations for the average years of schooling. To account for the possibility of endogeneity, this variable was lagged by one year when used as an independent variable in the regressions.

4. _Public Expenditure on education per capita (US$)_ . Public expenditure on education consists of public spending on public education plus subsidies to private education at the primary, secondary, and tertiary levels. To account for the possibility of endogeneity, this variable was lagged by one year when used as an independent variable in the regressions.

stock more accurately than the traditional gross or net enrollment ratios. Their most recent version of the data set also takes into account changes of school duration over time within countries.

- 13 This data set uses 3 main sources of data.  They are the OECD database on education, national censuses or survey published by UNESCO’s Statistical Yearbook and censuses obtained directly from national statistical agencies’ web pages.  Based on reports from its member and other non-member countries, the OECD has published detailed information on educational attainment, beginning at the end of the 1980s.  This information refers to the population aged 15 to 64 broken up in different age groups and this is the cornerstone of the Cohen-Soto data set for high income countries.  The main advantage of the OECD data set is that the information is presented in a standardized form across countries.  Cohen and Soto extend the study performed by the OECD to missing periods and countries.

One key difference between the Cohen-Soto dataset is in the methodology for extrapolating the missing data. Barro and Lee extrapolate missing data for the whole population either backwards or forwards to obtain educational attainment for missing years. As opposed to using the whole population, Cohen and Soto utilize estimates for age-specific groups, which they argue tend to result in more reliable estimates. Cohen and Soto also claim that for some countries, they had more recent census information that that used by Barro and Lee.