Special Note: Please note that this scenario is meant to be read as entertainment, not as an accurate prediction of the future. Also note that the viewpoints and opinions that may come across in this scenario are not necessarily the viewpoints and opinions of the author.
In the year 2030, a series of laws in North America finally made it mandatory for all residents to have at least a high school diploma. Year-round schooling throughout the continent will enforce the idea that "a solid education and a hard-working attitude is better than ignorance and laziness." An equal law would follow in the People's Republic of China five years later. Ten years later, it would become the law in the United States of Europe and in the Eurasian Union. People who fail to graduate high school or acquire a GED will be collectively referred to as the Global Intellectual South.
The legislated punishment for not having a high school diploma includes disenfrachisement, the complete loss of citizens' rights, and the inability to acquire or retain a driver's license of any type. It will take a significant amount of computer skills to graduate high school by the year 2025 (since only physical education classes will not require the usage of a computer of some kind). No computer skills equals no high school diploma equals no citizens' rights. There is no retroactive cut off date for people to be included into a grandfather clause; all citizens over the age of 18 must have at least a high school diploma to maintain their civil rights. High schools (and school boards) may legally keep students until they are 35 years old (up from 21 years of age as of 2010) so that everyone can have a chance of having a high school diploma (and full civil rights).
Married students would be allowed to continue their studies provided that both spouses attend the same school and are at least 21 years of age as of their official wedding day. The world of academia would be more tolerable to unwed mothers and married mothers who are trying to raise their children and get their high school diploma (that will be mandatory in a future society). In addition to the amendments making it mandatory for the government to help people find housing and jobs, the high school diploma helps keep literacy levels high in males and females. This "piece of paper" (later becoming completely electronic and running on solar power) also marks the beginning of the end for humans in dangerous and unskilled jobs; any job that has a likelyhood for non-intentional fatalities (read: deadly occupational hazards) will be relegated to robots.
These robots will be maintained by the humans in "safe" white collar office jobs. Had every adult citizen had at least a high school diploma during the Great Recession, then the effects of the layoffs might have been mitigated somewhat. Since humans will not able about to operate firearms under any circumstance or drive vehicles instead of using a chauffeur robot, forcing people to have a high school diploma will motivate them to jobs where they design the robot soldiers/patrolmen and create the robots that will drive the hovercars of tomorrow. Army jobs tended to be the workplace for people without high school diplomas; high school diplomas can be seen as the "papers of peacekeeping" that would finally see these uneducated specimens displaced.
By the year 2050, there will be no more "blue collar" jobs left in the world and even "burger flipping" jobs will require that the person be at least 18 years of age with a high school diploma (raised from 15 in 2010); promoting life-long education and discouraging dropping out. When looking ahead another 55 years to the year 2105, a twelfth grade education in the United States of Earth will be roughly equivalent to a PhD-level education in an early 21st century North American or Western European university.