|The method to fairly split a cake between two people is tried, tested,
and mathematically proven. One person gets to cut the cake and the other
gets to choose which slice they get. To get the biggest piece of cake,
the cutter must split it fairly resulting in no hard feeling between the
In American politics, however, cutting states into electoral districts
doesn't have a similarly fair method. The political party in charge
often decides where the electoral lines are drawn and does so in such a
way to gain an advantage - a process called gerrymandering. But now
researchers from Carnegie Mellon University have come up with a way to
extend the cake cutting technique to electoral redistricting to make the
system a lot fairer.
With the new approach, one political party gets to draw an electoral map
that divides the state into the agreed number of districts. The second
political party then chooses one district to freeze so that no more
changes can be made to it by either side. They then get to redraw the
rest of the map.
Once the new map is complete, the first political party freezes one of
the new districts so that no further changes can be made to it, and is
allowed to redraw the rest of the map again. This process goes back and
forth until every district within the state is frozen. In Pennsylvania,
for example, this would require 17 cycles as there are 18 districts.