IMHO I believe the answer to this question is “it depends.” In industry, the answer will always be around demonstrating what value you can bring to the table, and accordingly, why a customer should pay a premium for that. I would highly recommend talking to professionals in the field(s) that you want to eventually leverage your PhD into, and get their opinions on the value of their PhD’s to help you understand how you can flourish in your chosen specialty.
Let me caveat this however by saying the following: I do not have a PhD, but I find the endeavour personally and, depending on how well you can translate your PhD into economic value, professionally, very worthwhile.
Now, I am an Engineering and Project manager in the oil and gas industry, and have nearly 12 years’ experience in the production and management of engineering for projects greater than $US 1Bn. My largest project was over $US 40Bn, and I have worked with, and been served by, many engineers, scientists, and other technologists of many disciplines.
I have encountered many people with PhD’s in that time, most of whom were good people to work with. Almost to an individual, no one ever cared to emphasise their PhD, and in many cases, most chose to suppress it in favour of demonstrating the value delivered on previous projects and engagements that mattered to my needs as a manager or client. Most of the professionals with PhDs who we were paying real money for were not actually delivering any services or products that was connected to their PhDs. However, they were specialists in their fields, and their PhDs were almost always related to their chosen specialty. So if you had studied a PhD in geology or civil engineering (very common), then it would make sense for you to leverage your PhD into a geotechnical engineering firm where you would often be marketed to your client as, eventually, a Principal Geotechnical engineer or similar. This is a specialised role, with a narrow scope (same applies for any discipline), and if you are actually good at your job, you will be high in demand around town. Clients, whilst not necessarily paying an above-market rate for you, will likely insist that they “want you” as part of the delivery team because you are known to be credible at what you do. The PhD itself will have very little to do with that, but you will be rewarded if you are able to translate what you learnt from the PhD into delivering a service your clients will pay real money for. I have had these kinds of people work for me before, and I would seek them out again, but they never emphasised their PhD to me. In fact, I’ve worked with people who were exceptional at what they did, very highly regarded not just in my country but in others around the world, who didn’t have a skerrick of post-graduate education.
If you were to study a PhD (in Psychology say) and tried to leverage that into a non-related field (like management consulting), then the question of value will be even more poignant for you. In this instance, you would likely be relying on the “general” skills that a PhD would afford you (not that they are trivial by any means), and again, you would need to demonstrate to a buyer of your skills that your PhD provides greater value than someone else who may have more direct industry/ field related experience. Firms and industries where these generalised PhD-related skills might be valued (e.g. some investment banks, blue chip corporate strategy companies) are open to candidates with PhD’s but again, you would be required to demonstrate how your PhD translates into products and services your customers want to buy, and even pay a premium for.
I can appreciate the dilemma of someone contemplating the study of a PhD as it is, indeed, difficult to truly understand what kind of value you can demonstrate to a buyer at the end of it. Brian Rushton’s narrative is a fine account of the individual kinds of skill that a PhD can develop, but in industry, I would treat such skills as a given. Moreover, Brian’s description over emphasises the individual skill component, and is notably silent on other critical individual, team, and other “corporate” attributes that are necessary for success in industry. Brian mentions time management: again, this is something that I would expect a graduate engineer to be well on top of by their first or second year in work, so why, as either your manager or your client, should I expect this to be a differentiator for you? Especially given that you’ve invested some three or more years of your life developing this skill! Likewise, Brian also mentions being able to see many possible solutions. Creativity is a valuable thing, but in my industry, this must be executed with discipline, and applied with the necessary soft (emotional intelligence) skills to translate ideas into solutions that can be implemented successfully within a corporate risk and financial framework. I have often come across so-called “experts”, some with PhDs, who waste a lot of peoples’ time and money with ideas that are insensitive to the corporate, political, project and commercial realities surrounding them, and this often harms their reputations. Understandably, their ideas are not implemented, and these kinds of insensitive people are not hired again. Finally, the other skills that Brian mentions (project and cost management, business skills) are fine but these are carried out on a small scale. My question is: clients will pay for demonstrable experience, so how are you going to convince your future employer or client that they should pay good money to entrust you with a project or business that may exceed your PhD undertakings by a factor of thousands, if not tens or hundreds of thousands, or millions?
So my question is: why should I, either as your manager or your client, be prepared to pay a premium for your skills from a PhD when they can be honed by someone else working “at the coal face” in a demonstrable way over the same amount of time as your PhD? This question will vary depending on your industry. In my industry, real value comes not with the PhD, but your demonstrated experience in delivering valuable services and products, over a sustained time, to real customers. In other, very highly specialised industries, the PhD may serve as an entry point, after which your work performance will likely prevail.
I’ve really emphasised the “economic” aspect of the PhD in my response, and I tender it not to discourage you, but to help you to think very deeply about why you wish to do one before you decide to take the plunge. If you do decide to do one, then I wish you to do so with your eyes open, and, most importantly, sincerely wish you the very best of success with it, both personally and professionally.