There are a number of points to consider when deciding whether or not to go to graduate school, and blogger Jon Wilkins lays them out in a post at Lost in Transcription. First, he says that you should consider your lifetime earning potential. He notes that while people with advanced degrees do tend to have higher salaries, but adds that "if your primary consideration looking forward is monetary, this is not the right path for you."
Wilkins then says to think about what you want to accomplish during your life. "Imagine that you have just learned there is an asteroid heading towards earth, and you have thirty-six hours to live. Would you rush to grab your Greek edition of The Republic? Would you see if you could crack that one really hard problem from this week's problem set?" he says, adding if you see yourself saying 'yes' to one of those questions, grad school might be the place for you.
But some people, he adds, will still be unsure. For that uncertain slice, he says to look into whether you could have your grad school tuition covered by a fellowship and to determine whether a graduate degree is needed for your long-term career goal. In the end, Wilkins writes that "going to grad school is a good way to find out if you'll like grad school" and if you figure out it isn't for you, you don't have to stay. "So if you think you might like grad school, give it a go, but keep the escape hatch in mind," he advises.