Graduation rate is mostly student related. If a college has stronger students in an academic sense, it will have a higher graduation rate. For example, a college where most frosh were A students in high school with 32-36 ACT scores (or SAT equivalent) should be expected to have higher graduation rates than a college where most frosh were B students in high school with 20-24 ACT scores (or SAT equivalent). If a college has better financial aid and/or students from wealthier families, it should be expected to have a higher graduation rate compared to colleges with academically comparable students, due to fewer students dropping out due to running out of money.