In 2001, for example, Congress received a report it requested from the U.S. Department of Education called “Study of College Costs and Prices, 1988-89 to 1997-98.” It conclusively established that no relationship exists between tuition increases and federal and state aid.

Two years later, the Education Department produced “Congressionally Mandated Studies of College Costs and Prices.” It showed the results of four studies on college financing. No link.

The National Commission on the Cost of Higher Education came to the same conclusion in its 1998 study, “Straight Talk about College Costs and Prices.”

And, as we reported last month, the National Conference of State Legislators stated in “Transforming Higher Education: National Imperative-State Responsibilities” that tuition increases result from inconsistent levels of state support, and students are the ones who pay.

For ACE’s survey of the research, go to www.acenet.edu and select “Finance and Student Aid” (“view all”) under “Topics.”

Another survey released in January showed that price sensitivity is a growing factor in students’ college choices. The annual “Freshman Survey,” which comes out of the Higher Education Research Institute (www.gseis.ucla.edu/heri), found that the number of students choosing not to attend their first choice college upon acceptance has climbed from 30.2 percent to 32.7 percent. Of those attending their second, third or fourth choice colleges, cost was cited as the number one reason why. The study did not indicate how many students are accepted but cannot afford to attend college at all.

So arm yourself with the data when you visit your state and national elected officials: The only hike that happens when Congress and states fairly fund aid programs is in the number of kids who can go to college.

The lead article of the Winter 2007 issue of The Review of Higher Education tackles that question. Phil Umbach, assistant professor of higher education at the University of Iowa, used data from the Faculty Survey of Student Engagement, which is administered to 132 colleges and universities, to examine three questions:

■  Do contingent faculty engage students in good practices less frequently than their tenured and tenure-track counterparts?

■  Does the proportion of contingent faculty on a campus affect the frequency that faculty engage in good practices?

■  Does the effect of having a contingent appointment vary among institutions and, if so, can these difference be explained by institutional characteristics?

Umbach approached these questions from a framework that applied social exchange theory to his study. That is, individuals will show greater commitment to an organization when they feel supported and rewarded. He documented faculty behaviors that have been shown to improve student learning and development (such as faculty-student interaction, active and collaborative learning techniques, setting high expectations and so on). He also looked at the data on how faculty in the survey structured their class work inside and outside of class.

The results of this examination are not surprising, especially from the social exchange standpoint. On average, Umback found, relying heavily on a contingent workforce does not allow for many of the instructional behaviors that engaged students and their teachers prefer. Part-time faculty have less time to prepare for class, challenge their students less through active and collaborative techniques, and interact less with students outside of class.

By type of institution, however, Umbach found greater disparities in part-time and full-time faculty performance. The difference at doctoral and master’s granting institutions was greater.

From the perspective of students and those wanting to improve the undergraduate experience, Umbach’s study provides ammunition to advocates of greater support for part-time, adjunct and nontenure-track faculty.