CNBC Marathon explores if why the education system in the U.S. is struggling by taking a hard look at the Common Core, teacher’s salaries and sex education. First implemented in 2009, Common Core was an ambitious initiative to revolutionize the American education system. National leaders from Bill Gates to President Obama supported the idea and it cost an estimated $15.8 billion to implement. Years later, research showed the new curriculum had minimal impact on student performance. So why did Common Core fail? Can a common curriculum be successful for all students? At the same time, teachers earn nearly 20% less than other professionals with similar education and experience, according to the Economic Policy Institute. In many states, their wages are below the living wage, forcing teachers to seek secondary jobs to supplement their income or leave the profession all together. So why are teachers paid so little and how can the U.S. fix that? And the majority of U.S. students report they've had sex before graduation, which means the type of sex education they receive can be a big deal, for themselves personally and for the economy. The federal government doesn't have any official regulations for what schools must include in sex education curriculum, which has lead to inconsistent lessons across the country. Watch the video above to learn why sex education is so crucial for the economy and what happens when some students are left behind. CNBC Marathon brings together the best of CNBC’s education coverage on YouTube. Chapters: 00:00 Introduction 00:31 How Common Core Broke U.S. Schools (Published Aug. 2021) 14:30 Why Teachers Are Paid So Little In The U.S. (Published Dec. 2020) 25:51 Why Sex Education Is So Bad In The U.S. (Published Dec. 2021) » Subscribe to CNBC: https://cnb.cx/SubscribeCNBC » Subscribe to CNBC TV: https://cnb.cx/SubscribeCNBCtelevision About CNBC: From 'Wall Street' to 'Main Street' to award winning original documentaries and Reality TV series, CNBC has you covered. Experience special sneak peeks of your favorite shows, exclusive video and more. Connect with CNBC News Online Get the latest news: https://www.cnbc.com/ Follow CNBC on LinkedIn: https://cnb.cx/LinkedInCNBC Follow CNBC News on Facebook: https://cnb.cx/LikeCNBC Follow CNBC News on Twitter: https://cnb.cx/FollowCNBC Follow CNBC News on Instagram: https://cnb.cx/InstagramCNBC #CNBC Why The Education System Is Failing America | CNBC Marathon