Link Between Tuition Cost and Education Accessibility

Free College
Unfortunately, there is not a lot of literature about the idea of 2 years free college. There are certainly many countries, like those in Scandinavia, that offer their citizens free higher education. Yet there has not been much in the way of case studies as to the merits of offering 2 years' free college. Most of the knowledge on the subject derives from demand theory, which states that cost is a barrier to purchase. This is especially true when much of college education is framed in terms of cost-benefit analysis. This is clearly an area where there is a need for further study, since there is so little direct literature on the subject.
Behrman, Pollak & Taubman (1989) discuss the unequal access to financing for education. The study focuses on the relationship between family size, family resources and financing for education. There are many instances where family structure is an important element in determining the level of access to financing. Basically, children in larger families generally have lower access to education. This matters in the discussion about free college tuition for the first two years, because unequal access to financing is a barrier to education. The key takeaway is that free tuition would help lower the barriers to education, which would help improve access.
Heller (1999) looks at the issue of tuition and public college enrollment. The underlying logic here is that there is a correlation between college education and income. Thus, there is a question of how to ensure that college education is accessible for all. The Heller study focuses on applying demand theory to the idea of college education. The study shows that there is a link between tuition and enrollment rates. This will also depend on the income level – the study focuses on different races and there's definitely a link. People who have more money are have lower price sensitivity.
Johnstone (2003) discusses how cost-sharing can help improve access to higher education. The author looks at the different payers –parents, governments and taxpayers. There may be resistance to splitting the costs, but the author notes that the ideal model might actually be to have this cost sharing.
There are many structures to cost sharing, but in the United States there is this ideological opposition to government help in cost-sharing for higher education. An increasing reliance on private forms of higher education is ultimately going to be an indicator of enrolment behavior. In terms of public policy, there is a balance of equity for education and the need for revenue.
Barrow & Rouse (2005) take a look at the other side of the equation – whether it is worth it to pay for college. The idea of education as something that is an investment matters because it reflects the idea that college being an investment means that one must consider the cost. If cost is not considered, then cost is not a barrier; but if this is a rational economic question then the value of education is the key.
All told, there is some literature that outlines and supports the fundamental arguments, but there is nothing too specific. The basics of demand theory definitely suggest that offering free college education for two years would certainly increase enrollment and lower barriers to access to education.
References

Barrow, L. & Rouse, C. (2005) Does college still pay? The Economists' Voice. Vol 2 (4) 1-8

Behrman, J., Pollak, R. & Taubman (1989) Family resources, family size and access to financing for college education. Journal of Political Economy Vol. 97 (2) 398-419

Heller, D. (1999) The effects of tuition and state financial aid on public college enrollment. The Review of Higher Education. Vol. 23 (1) 65-89

Johnstone, D. (2003) Cost sharing in higher education: Tuition, financial assistance and accessibility in a comparative perspective. 39 (2003) 351-374.