From a reader:

Jonah, I am an engineer completing my masters degree right now…. I will not be getting a PHD. I just read the post and the thread and I am extremely angry. You are absolutely correct that it is harder for liberal professors to get private sector jobs. In fact it is harder for ANY PHD to get a private sector job. It works as follows:
If you get a PHD you are only going to be able to find work which is directly related to your PHD or Masters research (this is what they told me when I was an undergrad). You will not get a job designing engines if your research is in manufacturing. Also, an engineer with a masters can do pretty much everything that an engineer with a PHD can do. Knowing this, why in the hell would a company pay a PHD $100k/year when they could pay a Masters $70k/year for the exact same work? The only reason (outside of nepotism) is if they want to say “this was designed by so&so, PHD”. If you complete a masters degree though, you still have many options. You do not have to go to work in your research field. You can work for almost any company in your discipline doing what ever that company does. I am not going to get a PHD because I don’t want to be tied down to one small area of my discipline.
As for your data to back up your claim, I can offer this little gem:
I had a coop (internship) at a nuclear power plant for seven months. There were many employees there as you can imagine. Out of all of these employees there were around 200 engineers. Out of all of these there was only ONE PHD.
Those arrogant pr**ks over at DeLong’s website are basically saying that I, and every other engineer out there are morons. I believe that the reason they are in academia is that they were too chicken shit to become real engineers and get liscensed. Because once you are liscensed, you are responsible for your work. Your job is on the line every time you sign off on some component, mechanisim, circuit. If what you worked on fails, than just like a doctor you can and will be sued, or at least your company will be. It is alot of pressure when you think about it. I suspect that those in academia just wanted a comfortable salary, easy summers, and enjoy teaching.
If you want anymore insight into undergrad engineers today I would be happy to tell you what I have observed. There are many reasons on why you shouldn’t go to graduate school.
If you post anything from me, please don’t put my name. I still have to defend my thesis.