If we look at the spending on education, we do not see any spatial or temporal patterns. Overall, the percentage is relatively stable within 2 percentage points for all countries and for both the GDP and the total expenditures.
If we look at the map below, it is striking that significantly more people in the global North have a tertiary degree than in the global South. Furthermore, a trend can be observed whereby the proportion of people with tertiary education is slightly increasing worldwide.
The results of the Pisa studies were only collected in the industrialized nations or are only available from these nations in our data set. No significant temporal or geographic patterns can be identified here.
Comparison of Spending and Success
As we can well see, the economic performance of individual countries is increasing worldwide. It is also evident that countries with a higher GDP per capita tend to have a higher number of people with a tertiary degree. A less clear pattern emerges in a country's percentage investment in education in relation to the GDP per capita.
Comparing GDP per capita with Pisa data, Mexico and Chile are significantly below average in both variables over the years. However, the number of countries with corresponding data is comparatively small and they are mainly industrialized nations, which is why it is difficult to make a general statement here.