This week in Philadelphia, the Democratic Party is expected to officially confirm Hillary Clinton as its presidential candidate. But the surprisingly competitive primary race doesn’t come without considerable concessions to the more liberal wing of the party supporting Sen. Bernie Sanders (I-Vt.).

Earlier this month, Clinton updated her presidential platform to more boldly address affordability in higher education. Her updated proposal would grant tuition-free access to public universities for families with annual incomes less than $85,000, tacking on an additional $100 billion to her original plan. The tuition threshold would build up over time so that by 2021, families making less than $125,000 a year would also have access to tuition-free college.

Clinton’s new position is just the latest piece in the discussion to improve higher education, which has centered around lowering student debt and increasing the accessibility of the expensive four-year college model. But there’s a larger question to be asked: Is the current model the right one?

The 1944 GI bill, which offered free tuition for World War veterans, launched a wave of enrollment in “traditional” four-year institutions that has yet to abate. A vast array of films and books celebrating the “college experience” and numerous presidential administrations that have exhorted students to commit to higher education have pushed many to see a four-year university education as the best option after high school. It’s a model that delivers both prestige and income potential not found in community colleges or other trade schools.

Forty percent of college-age Americans are enrolled in degree-granting institutions, and a bachelor’s degree is closely tied to financial achievement later on. In 2013, median earnings for young adults with degrees were $48,500, compared with $30,000 for those with a high school diploma or its equivalent. Yet not all who enroll in school complete a degree, and enrollment is no guarantee of work: A Department of Education survey found that 84 percent of 27-year-olds had some college education, but only 34 percent achieved a bachelor’s degree or higher. Many were also left with debt and bouts of unemployment.

Higher education models are policy choices that include trade-offs with regard to cost to the public, government subsidization and enrollment. The U.S. system emphasizes high subsidization but relatively low enrollment when compared with other countries. Our more federalist system offers control of higher education systems to states and local governments, which decide tuition prices and the cost of education locally, leaving room for a large number of private colleges and universities.

Many higher-education institutions in the United States have a strong emphasis on research along with a uniquely American focus on the liberal arts — a high level of academic excellence, but one that is not necessarily tied directly to students’ economic participation or preparation for employment. European countries, in contrast, have “dual education systems” at the post-secondary level, in which higher education can also take the form of specifically vocational work.

Some prominent critics of the U.S. system argue that we need to offer new routes for job training that doesn’t rely on costly research institutions. Kevin Carey of New America, for example, has suggested that technology and the Internet would spell the “end of college” as we know it, allowing more people to gain skills without submitting to the typical four-year model. Others predict that most higher-ed institutions won’t survive this disruption.

Are the expensive, research-focused academic institutions in the United States the best outlets to offer the job training needed in our rapidly shifting economy? Should “job training” even be the main goal of higher education? And what about alternative systems that are less costly and easier to access — whether community college, vocational training or apprenticeships? Should we be taking lessons from other countries as we attempt to reform our higher-education system?

Over the next few days we’ll hear from: