The TIMSS study is another international study to look at for information about science education in various countries. Most studies of education policy suffer from the same defect of not having a truly experimental design:
http://norvig.com/experiment-design.html
that is, most of those studies don't have random assignment of students to treatment and control groups, but rather look for correlations between academic performance and other observations, with nothing in the study design being able to give assurance of causation.
Science textbooks used in the United States have long been very lousy,
http://www.textbookleague.org/
and as I have had a chance to see science textbooks from other countries, particularly Taiwan, China, and Russia, I hazard the guess that improving textbooks in the United States would help more learners learn science more successfully. General improvement of teaching technique along the lines discussed in another current HN thread
http://news.ycombinator.com/item?id=2960085
would probably also be helpful, but the policy incentives needed to improve teacher performance are not easy to come by in the United States.
After edit: To answer a question asked in another comment below the submitted article, scientific illiteracy is an important public policy issue because scientific illiteracy in a democratic republic results in voters voting for stupid policies because they don't understand science. The reason to know science isn't just to get a job, but to be a more thoughtful citizen and voter.