Since BPS first announced their initial proposals for a new student assignment plan, grandfathering of current students has been a very hot topic. Of course, there's a clear tradeoff here. Grandfathering students (and possibly their siblings) with transportation could be very expensive. In fact, it could lead to transportation costs increasing under a new plan, at least temporarily. On the other hand, forcing thousands of students to switch schools in September of 2014 when the new plan takes effect would be extremely disruptive to families and schools.

BPS quickly stated that there would be grandfathering under a new plan. They are currently proposing to grandfather students in their current school through the final grade available in the school. Transportation would still be provided for the first six school years under the new plan (2014 - 2020). Children in 6th grade or higher could receive a T pass to continue to attend their school after their grandfathered transportation ends. They are not, however, proposing any grandfathering for siblings. Under the current proposal, if your child is starting school in 2014 and has siblings in a school that you cannot choose under the new plan, you would be forced to send your younger child to a different school. You would get sibling preference to transfer older siblings into the younger child's school once he or she has been assigned.

There have been many calls to grandfather siblings. The Quality Choice Plan proposed by City Councilor John Connolly and other elected officials called for grandfathering siblings with transportation indefinitely. An op-ed in today's Globe discussed what preventing siblings from enrolling in a school would do to the community there. But BPS does have a valid concern. If siblings are grandfathered with transportation, BPS could have to maintain otherwise unused bus routes for years at great expense.

But what about allowing families to enroll siblings but not providing transportation? This would be a no-cost alternative that would allow many families to stay at their current school and keep their kids together. One concern with this idea is that not all families would be able to take advantage of this. Middle and upper-class families would find it much easier to get their kids to school than lower-income families would.

It occurred to me that we already have a form of grandfathering without transportation. If a family moves from one BPS zone to another, they can currently keep their child in his or her current school as long as the family provides transportation. I decided to look into this using the data provided by BPS. There's no cut and dried way for me to identify children who are being grandfathered, but I used the following criteria:

• I looked only at children in grades K1 - 5 where the walk zone is one mile.
• I identified students who attend school in a different zone from where they live.
• I only looked at children who live more than 1.1 miles from the school they attend to eliminate students who can cross zone lines because they live in a school's walk zone (walk zones can actually be slightly larger than 1 mile so I used 1.1).
• I eliminated any child who receives bus transportation. These children may have special needs or some other reason they receive bus service but are clearly not being grandfathered without transportation.

This gave me a list of 389 children who appear to be grandfathered into a school outside their home zone. Of these, 306 or 78.7% qualify for free or reduced price lunch. The district wide percentage is 70.5 according to this dataset.

First I thought this was strange. I had assumed that better-off families would be more likely to take advantage of this grandfathering than lower-income families because they would be more likely to own a car. However, it did occur to me that lower income families move much more often so this may account for why they make up a larger percentage of this group.

One thing is clear though. Low-income families are taking advantage of this rule. So it may not be a good assumption that grandfathering siblings without transportation would disproportionately benefit middle-income families. And many low-income families would certainly prefer this to no grandfathering for siblings at all. So I strongly recommend that BPS consider this option.

One more thing that BPS should consider is giving families who want to transfer a grandfathered child into a school the child is eligible for under the new plan preference over other children applying for a transfer. This would help reduce the impact of grandfathering during the six year period during which BPS proposed to provide transportation to grandfathered students.