Ideally there should have been a link between the two, however unfortunately there is no correlation between the number of PhD's and the amount of innovations. The fact that PhD has been made compulsory to get a job in a teaching/research Institute, the quality of PhD has seen a dramatic decline. If this is de-linked only those interested in research would pursue PhD and the quality of the same would be of high standards leading to innovations.
to some extent there is correlation between Ph. D. and innovation. In sciences and technological streams, the researchers generate new machines, come out with new species and even patent there research too. In case of commerce, management and OB researchers delve upon new ways of doing business, which is a component of innovation as explained by Schumpeter. The list is never ending.
I'm very interested in the underlying thought of Rina. Is there evidence to conclude that the quality of PhD has seen a dramatic decline? And regarding to the main question, is it about PhD in Innovation or PhD in general. That makes a difference.
not necessarily true. actually the quality of various researches leads to inventions. not all PHds specifically lead to great inventions. for example there is a new chain evolving in transportaion from,telematics, drones to unmanned vehicles carrying people as in dubai, drones being used for various activities etc. These need not necessarily involve research/Phds being awarded but could be due to innovation and new ways of handling things. similarly iphone concept may not have anything to do with phd. it could be due to inhouse researches in various fields. In brief exact co relation may not be ascertainable or may not even be existing.
While, there may be a correlation between the number of PhDs and innovation, I think to be more accurate we must add and control for additional variables. These variables must include the subject of the PhD and the nature of the research conducted. Some fields like hard sciences, healthcare, and technology lend themselves to greater innovations than humanities or certain soft or social sciences. I think a r Pearson Coefficient can be used as a quantifiable measurement or perhaps Spearman which the Pearson will measure the correlation between PhDs and innovation. however, this must be controlled for the type of PhD.
I do not believe that in general the quality of PhDs has decreased because the qualifications for orignal or different perspective research or research on a different population that adds to and fills a gap in the litereature is still the main requirement. The vigor is still there. I just think that there are a few unscupulous for profit degree mills that offer PhDs that one needs to steer clear from. They are the exception rather than the rule.