In a new article from the Economist, a paper by the American Enterprise Institute finds that students nowadays are spending less time studying than they did a generation ago.:
"Study time for full-time students at four-year colleges in the United States fell from twenty-four hours per week in 1961 to fourteen hours per week in 2003, and the decline is not explained by changes over time in student work status, parental education, major choice, or the type of institution students attended."
The thing is, it's hard to explain why this is happening. It's not because of improvements in education technology, student's work status, parental education, major choice, nor is it due to the type of institution attended. But the said Economist article shared one book by Andrew Hacker and Claudia Dreifus that puts forward one explanation: the professors teaching aren't doing their jobs good enough because of their research activities:
"[P]rofessors are spending less time with their students (while also charging them more) in order to give themselves more free time to produce worthless research."
From the field of economics, part of this theory is true. That part is where economics professors are indeed undertaking research at the sideline while teaching economics courses. But that's natural, and in fact, it should be encouraged. It's not so much that they can get extra income from their research (above what their receiving from their teaching work). They get to be more specialized in their field and that's part of getting professional development. It also prevents their economic knowledge from being stagnant. Pursuing research helps them be aware of what is the latest in the economics field.
As for the other part, we may never know really if the professor consciously do not concentrate on their teaching as how they should be. We'll have to rely the different checks and balances instituted by the school--student evaluation, department evaluation, etc. It might really well be the case that there are just some bad apples in the mix of otherwise excellent ones. It would really be unfair for economic professors who find satisfaction in encouraging student opinions (or ideas) about current economic trends. And there are a lot of those.