The short answer is carefully and soon.

The median family income in the US is about $51,000. The “sticker price” for four years at a state college is about $100,000—and most don’t graduate in four years. Very few families are affluent enough to enjoy the luxury of sending you to college to:

• Find yourself,
• Intellectually enrich yourself,
• Or just have a good time.

Post-secondary education today is a financial investment decision:

• Half of all four-year college graduates are under employed or unemployed.
• Dropouts are stigmatized in the job market,
• One in four student loans is in default or delinquency.
• Almost one third of 18–34 year olds are living with their parents.

By entering college without having identified a marketable major, you will have put yourself at a disadvantage:

One of the criteria for choosing a college is strength in your intended field of study. Selecting a school that is great in CS isn’t going to work out very well if you wake up one morning and decide veterinary medicine is your chosen field.

You can’t make an intelligent decision about student loan debt without a targeted job. For example the amount of student loan debt you assume would be different if you hope to be an engineer (target salary=$60K) vs school teacher (target salary=$40K).

College has become unbelievably expensive. Students who enter without planning may change majors once, twice, even three times. This completely sabotages their (hopefully) carefully laid out financial plans, often resulting in withdrawal or excessive loans.

Given the high cost of college and the significant shortage of good jobs today majors need to be marketable. Art history is a hobby not a viable college major.

My recommendation is to explore marketable majors while in high school. Go to career night at a local hospital. Visit STEM night at a nearby community college. Arrange “shadow days” with professionals, join clubs, start clubs, learn to code—EXPLORE.

Here are a couple anecdotes about majors:

Ragin’ Cajuns

I was in Dallas to see the Buckeyes win the national championship in January 2015. Coming home through DFW I stopped to grab a BBQ sandwich and joined in a conversation with a couple recent graduates of the University of Louisiana Lafayette—Ragin’ Cajuns.

One was behind the counter doling out brisket, chips, and beer, and the other was a passenger catching a plane to his new energy sector job in Houston. This is just one example of how choices of college majors today have widely disparate outcomes.

Wandering in the Wilderness

Janice entered a very selective college “major undeclared.” (The school is very supportive of this action.) She followed several different avenues of study, never quite finding a clear direction. After six years she graduated with a BA. She is $132,000 in debt. The only job she can get is substitute teacher.