【2009年阅读Text 3 第5段】
On the contrary, constraints on improving productivity explain why education isn't developing more quickly there than it is.
①As education improved, humanity's productivity potential increased as well.
②When the competitive environment pushed our ancestors to achieve that potential, they could in turn afford more education.
③This increasingly high level of education is probably a necessary, but not a sufficient, condition for the complex political systems required by advanced economic performance.
④Thus poor countries might not be able to escape their poverty traps without political changes that may be possible only with broader formal education.
⑤A lack of formal education, however, doesn't constrain the ability of the developing world's workforce to substantially improve productivity for the foreseeable future.
⑥On the contrary, constraints on improving productivity explain why education isn't developing more quickly there than it is.