Should grad students teach?

A student emails me a question:

Dear Prof. Mankiw, 

I am in the first week of my PhD in economics. I follow your blog and I have read the advice you have posted for graduate students. 

I have heard competing hypotheses about whether PhD students should teach during their studies. On one hand, teaching is a great experience and a CV-builder for hopeful future academics. On the other hand, teaching is a lot of work, and the opportunity cost of time for any PhD student is high. 

Do you have any advice about how a PhD student (and a big fan of your blog!) can reconcile these points? 

Cheers,

[name withheld]

Teaching is not necessary while pursuing a PhD, but it is usually a good idea for several reasons.

1. Grad students can usually use the money, and teaching is often a good way to make some.
2. Teaching improves your oral presentation skills, which will be crucial when you go on the job market.
3. You will learn whether you enjoy teaching. If not, you might consider alternatives to an academic career.
4. When you apply for jobs, teaching experience will be a plus for many schools that might hire you.
5. Teaching will help remind you why you fell in love with economics in the first place. That can be useful during those inevitable days when your dissertation research is not going well.
6. Teaching will provide greater variety to your day than if you are solely focused on research. The personal interaction with students will often lift your spirits.
7. When you are teaching, you can be confident that you are making positive contributions to society, and that feeling is also good for your mental health.

Let me also mention one risk: If you enjoy teaching, you might use it as a distraction from getting your dissertation done. The key is moderation. Teach some, but not too much.