It's often been said that a college education is the smartest investment you can make, and earnings statistics certainly seem to bear that out. Statistics compiled by the National Center for Education clearly show a wide disparity in earning power between those with a high school education and individuals who earned a college degree. Over their lifetimes, men and women who have attained at least a Bachelor's degree can expect to earn hundreds of thousands of dollars more than their high school-educated counterparts.

Male Workers

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Statistics for the year 2008 show that a male worker with a high school diploma could expect to earn an average salary of $32,000, lower than the $40,000 average for all education levels. In stark contrast, male workers with at least a Bachelor's degree had average earnings of $55,000, a full $23,000 more. Over a career spanning 30 years, that means a pay disparity of well over $600,000. The increased earning power that can be achieved with a college degree is enough to offset even the most expensive education.

Female Workers

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The disparity in earnings power for female workers is just as significant. The 2008 statistics showed that a female worker with a high school education earned an average annual salary of just $25,000. Again, this is lower than the average $34,000 for all female workers across all educational levels. On the other hand, female workers with at least a Bachelor's degree had average annual earnings of $45,000, a full $20,000 more for every year of work. That $20,000 a year figure becomes $600,000 over a 30-year career.

Widening Gap

One noteworthy finding from the numbers compiled by the National Center for Education Statistics is how the gap between high school and college graduates has widened over the years. In 1980, male high school graduates earned an average of $44,200, not far behind their college educated counterparts, who earned an average of $52,300. Just 28 years later, the gap between high school and college graduates had widened considerably, to $32,000 for high school graduates and $55,000 for those with at least a Bachelor's degree. No doubt the demise of high paying manufacturing jobs that required only a high school diploma played a role in this growing earnings disparity.

Lower Unemployment

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College graduates have another important advantage that can boost their lifetime earnings even higher compared to their high school educated colleagues. The statistics reveal a strong correlation between educational achievement and unemployment, with those at the bottom of the educational ladder suffering the highest levels of unemployment. In December 2010, a month marked by high overall unemployment, high school graduates had an unemployment rate of 9.8 percent, while those with a Bachelor's degree had an unemployment rate of just 4.6 percent.