Generally, the answer is "No, the Ph.D. title hardly makes you worth more as you step far from your main area".
Typically, doctorate training prepares you to do research, and by the time you graduate, you will have accumulated research experience in your narrow area. So even in academic CS, you won't be particularly welcome if you did research in compiler theory, and the department is looking to hire somebody in Big Data. Moreover, your compiler theory research experience is hopeleslly useless if you decided to work in medieval German literature or neuropsychology or plant biology. They will hire the specialized Ph.D. in that area any day over you. They will hire a linguist who said they took a CodeAcademy class in Python over you even if the project calls for text mining for unique patterns of word use in XV vs. XVI century.
If you slip out to the big real world outside of academia, you will find that you will have surprisingly little to offer on top of a good MA graduate while wanting a higher price tag. Microsoft or Adobe or any other MakeUpNameSoftMetrics do not develop compilers, and instead they would want you to deliver good quality production code (or, worse, to oversee a team of programmers who do that). So ask yourself again.
Paul said here that Ph.D. develops "the skills to attack virtually any problem very deeply, if given sufficient time". I added emphasis, and I cannot stress this small print enough. My experience in industry is that the deliverable time is often yesterday, and few leaders have the patience for you to develop a perfect peer-reviewed published solution. It may not always have to be quick-and-dirty, but it is always have to be on time, so you need to have a better understanding of what the most important points and priorities in your project are which need to be addressed and accomplished first than academia can teach you.
Virmaior said here that McKinsey happily hires Ph.D.s as consultants. That, of course, is true, but it does not mean that they hire any Ph.D. in any discipline out of charity. They are looking for specific communication and business skills -- essentially for people who made the wrong choice by going to a Ph.D., or had no other pathway to continue with their traning, or in other words who have the mega brains to do really smart work, but may not find themselves happy in academia. The work environment in a consulting firm is anywhere from three to five times as intense as your Ph.D. -- not necessarily in the hours, but more in terms of responsibility. You may be well paid, but you are absolutely required to deliver. McKinsey specifically has an "up-or-out" model: at a time for the regular review, you are either so good that they promote you, or the company will be better off with you working for their competitor. Compare that to "Oh, you worked on this project for two years, and all your mice died because somebody turned the A/C off for the weekend? Ah well. Let's find you another project where I need a qualified technician but I don't want to pay the full time position benefits..." (As a side comment, McKinsey's pricing structure ends up being absolutely, over-the-top ridiculously expensive, may be because they hire so many Ph.D.s that still need to be molded into industry setting.)
To round the picture up, in government of any kind, you will find spending 25% of your time on filling compliance paperwork, be that a job in a public school, an IT support job in state capitol, you name it. This is as far as it can get from being able to come to work in shorts and sandals at noon to work through the night. As far as what Ph.D. is worth there: if you browse some jobs on usajobs.gov, you will find a scale of GS-## (government service at a given level), and the relevant level for a Ph.D. is around 12. I found these two pieces in my area:
In addition to the Basic Requirements:
For the GS-12, applicants must have either (a) one year of specialized
experience equivalent in difficulty and responsibility to the GS-11 in
the Federal Service or (b) a Ph.D. or equivalent doctoral degree in
statistics, biostatistics, computer science, mathematics, or a closely
where in turn level GS-11 means
In order to qualify for Mathematical Statistician, 1529-11/12/13, you
must meet the following:
Have at least a bachelor's degree that included 24 semester hours of
mathematics and statistics, of which at least 12 semester hours were
in mathematics and 6 semester hours were in statistics.
Have a combination of education and experience--at least 24 semester
hours in mathematics and statistics, including at least 12 hours in
mathematics and 6 hours in statistics, as show in A above, plus
appropriate experience or additional education.
Minimum Qualification Requirements for Mathematical Statistician,
Have one year of specialized experience, equivalent to the GS-09 grade
level in the Federal service that includes experience performing
statistical analyses on biological or biomedical research problems and
conducting reviews evaluating statistical methods, procedures, and
concepts involved with biological or biomedical applications.
So for that line of work, Ph.D. = Bachelor + 1 year. Don't quote me on this, job requirements keep changing, and I won't even bother putting links as these jobs expire quite quickly by SE standards.
As a silver lining, there are industry jobs where Ph.D. is required. However, these would be leadership positions in research-heavy types of work, and positions would be listed as "15+ years post Ph.D.; experience overseeing 10+ direct reports" or the like. By then, you will have retrained yourself into whatever the job really requires, so the Ph.D. is really just three letters after your name at that point. If leadership role is where your ambitions are, you should start taking classes in Business Administration immediately if your program covers arbitrary credits outside your major department.