The online journal Laborjournal has an interesting editorial on scientific ghostwriting (in German) that includes a number of legal cases in Germany and some interviews with ghostwriters. The author also contacted a company that says that they do not write doctoral dissertations. Writing as a medical student, they inquired as to the costs for a medical dissertation on a particular topic. They were given an offer of 5900 € for such a thesis, much less than the 7-10.000 € normally taken for a Diploma- or Masters-Thesis of about 100 pages.
The also include an interview with the authors of PlagScan, a so-called plagiarism detection system. They do concede that software only finds about 60-70 % of plagiarism, as we have demonstrated a number of times over the years. But the authors are confident that they can soon write a system that can even detect ghostwriting.
I'm not of that opinion. I know that I write differently when I am blogging than when I am writing a scientific paper. I have different styles. Trying to detect ghostwriting with software is just not possible. However, we as professors do have a chance to detect this if we have our students regularly submit drafts so that we can see progress. This, however, takes quite a lot of time, giving feedback on drafts. We have to meet with the students and ask hard questions like: where did you find this paper? We don't have that in our library....
And time is the problem. I don't know about you, but my day only has 24 hours. The more students I have, the less time I have to work with each one individually. If we are not reading the theses, why should the students write them? This creates a culture in which people can get away with submitting ghostwritten papers. Of course, what are they going to do when they have to write after their studies? They've never learned to do research, to structure, to write. So that will either ensure an expensive market for ghostwriters, or they will end up getting fired - if there is someone with the guts to call them out on their lack of skills.
The university system needs reforming, and it needs it yesterday. And not just in Germany, it would seem.