This is not time-series data. The study design here (a cross-sectional survey of varying countries, showing a bare correlation between two variables) is not adequate to show causation.
(By the way, the scatter of data points around the regression line in their plot suggests that the model is subject to large degrees of error in prediction.) It would take an experimental design (randomly assigning one group of teachers in the same country to receive pay raises while another group does not, with before-and-after comparisons of pupil performance) to show that paying teachers more results in higher pupil performance.
but none of those conclude that simply raising teacher pay, without changing teaching practices and perhaps also the composition of the teaching workforce, will have much to do with raising pupil performance in any place. Raising teacher pay systematically has been tried in the United States (notably in the state of Connecticut) and has not been shown to markedly raise pupil performance.
An economist who closely studies education policy has suggested that pay and other incentives be used to encourage the least effective teachers to seek other occupations while rewarding the most effective teachers with increased compensation and more professional support.
Such a policy, he estimates (showing his work in his article) would raise United States educational achievement to the level of the highest-performing countries. This is something worth verifying by experiment, although that will be politically difficult in any state of the United States
P.S. I'm curious about why the United States underperforms so much compared to salaries paid to teachers in the chart shown in the submitted blog post.
http://norvig.com/experiment-design.html
(By the way, the scatter of data points around the regression line in their plot suggests that the model is subject to large degrees of error in prediction.) It would take an experimental design (randomly assigning one group of teachers in the same country to receive pay raises while another group does not, with before-and-after comparisons of pupil performance) to show that paying teachers more results in higher pupil performance.
http://escholarship.org/uc/item/6hb3k0nz
There have been hundreds of studies of educational interventions over the years,
http://www.amazon.com/Visible-Learning-Synthesis-Meta-Analys...
and many thoughtful international comparisons of teaching practice,
http://www.amazon.com/Teaching-Gap-Improving-Education-Class...
http://www.amazon.com/Knowing-Teaching-Elementary-Mathematic...
http://www.amazon.com/Making-Learning-Whole-Principles-Trans...
but none of those conclude that simply raising teacher pay, without changing teaching practices and perhaps also the composition of the teaching workforce, will have much to do with raising pupil performance in any place. Raising teacher pay systematically has been tried in the United States (notably in the state of Connecticut) and has not been shown to markedly raise pupil performance.
An economist who closely studies education policy has suggested that pay and other incentives be used to encourage the least effective teachers to seek other occupations while rewarding the most effective teachers with increased compensation and more professional support.
http://edpro.stanford.edu/hanushek/admin/pages/files/uploads...
Such a policy, he estimates (showing his work in his article) would raise United States educational achievement to the level of the highest-performing countries. This is something worth verifying by experiment, although that will be politically difficult in any state of the United States
http://www.cato.org/pubs/journal/cj30n1/cj30n1-8.pdf
and perhaps in Britain as well.
http://www.economist.com/node/17849199
P.S. I'm curious about why the United States underperforms so much compared to salaries paid to teachers in the chart shown in the submitted blog post.