How much money do you need to earn to be happy?

They say that money doesnt buy happiness. As true as that might be, a 2010 study from Princeton University found that, while money doesnt necessarily create happiness, it certainly doesnt hurt. Up to a cap of $75,000 a year, salary increases dramatically affected how participants in the study rose above certain adversities. For example:

• 51 percent of divorcees who made less than $1,000 a month reported they felt sad or stressed the previous day, compared to only 24 percent of those earning more than $3,000 a month.
• 41 percent of low-earning study participants with asthma reported feeling unhappy, as opposed to 22 percent of the wealthier group.

"High incomes dont bring you happiness, but they do bring you a life you think is better," say the authors of the study at Princetons Woodrow Wilson School.

Careers that offer a national annual median salary of at least $75k

The Bureau of Labor Statistics (BLS.gov, 2012) most recent job projection numbers show six different jobs with national median annual salaries that meet or exceed $75,000 -- the amount of money the Princeton University study said some people need to earn in order to be content. The education requirements for these careers vary, but some require a bachelors degree. Each of these professions is projected to grow by at least 20 percent between 2010 and 2020; some are expected to grow even more.

1. Biomedical engineers. Biomedical engineering is a specialized field of engineering that focuses on developments in biology and medical science. This relatively new field is projected to grow in the coming years, with a 62 percent increase in jobs projected between 2010 and 2020 (BLS). The BLS indicates that a bachelors degree in biomedical engineering or the related fields of biology and engineering are some of the most popular educational paths taken by professionals in this career (BLS). Biomedical engineers made a national annual median salary of $84,670 in 2011 (BLS).
2. Computer systems analysts. Bridging the gap between computer programming and business, computer systems analysts made a national annual median salary of $78,770 in 2011 (BLS). The profession is expected to grow by 22 percent between 2010 and 2020, with an expected 120,000 jobs projected to be added during that time period. Its common for computer systems analysts to have a bachelors degree in computer or information science, according to the BLS, although some firms are also hiring business and liberal arts degree holders who know how to write code (BLS).
3. Environmental engineers. These professionals apply the principals of engineering to everything from soil science and hydrology to conservation biology and organic chemistry -- with a lot of Earth sciences in between. Many environmental engineers have a bachelors degree in the field, but chemical, civil and mechanical engineering degrees are also common. In 2011, these engineers earned a national annual median salary of $79,050 (BLS), and the projected job growth between 2010 and 2020 is 22 percent (BLS).
4. Geoscientists. A bachelors degree in one of the geosciences is preferred for this field, but with focused coursework in geology, degrees like biology, chemistry and physics may also qualify job applicants for a position in the growing field -- just keep in mind that some states require licensing. Geoscientists made a national annual median salary of $84,470 in 2011 (BLS). The profession is expected to grow by 21 percent from 2010 to 2020, adding a projected 7,100 more jobs (BLS).
5. Management analysts. In 2011, management analysts earned a national annual median salary of $78,490 while analyzing organizations and suggesting efficiency upgrades (BLS). A bachelors degree in management may help applicants get a start in this field, although many companies prefer to hire those with Certified Management Consultant (CMC) designations or masters of business administration (MBAs). Job growth in this field is projected at 22 percent, a whopping 157,200 jobs, between 2010 and 2020 (BLS).
6. Medical and health services managers. Also known as health care executives and health care administrators, workers in this profession made a national annual median salary of $86,400 in 2011 (BLS). Theres 22 percent growth expected in the field, which works out to 68,000 new jobs over that period (BLS). A bachelors degree in health administration is standard for the field, but specific requirements can vary by facility.

Salaries vary everywhere you go, but so does cost of living. While $75,000 may go far in Fargo, North Dakota, it may not be enough to meet living expenses in high-rent cities such as Manhattan and San Francisco. Even so, it would be nice to have the chance to earn at least $75k a year and find out for yourself if that amount, indeed, is the threshold to happiness.