Having more than one child in college usually lowers EFC and can increase financial aid

From the NYT's The Choice Blog, Mark Kantrowitz explains how a family may qualify for more financial aid if they have more than one child in college.

The expected family contribution (EFC) is the sum of a student contribution and a parent contribution. When there are two or more children in college at the same time, the parent contribution is split among them.
The student contribution may differ depending on the income and assets of each child. In most cases having more children in college at the same time leads to a decrease in the EFC for both and an increase in the amount of financial aid.
For example, let’s consider the financial aid eligibility of two hypothetical families, one with just one child in college and the other with twins. Assume that the college costs $30,000 a year. With one child in college, the EFC is $16,000, consisting of a $2,000 student contribution and an $14,000 parent contribution.
The financial need for this child is the difference between $30,000 and $16,000, or $14,000. With two children in college, the EFC for each child is $9,000, since each child gets half of the $14,000 parent contribution.
The financial need for each child is the difference between $30,000 and $9,000, or $21,000. So by having two children in college at the same time, each child gets significantly more financial aid.