Redistricting in Mexico

Redistricting is the redrawing of the boundaries of legislative districts for electoral purposes in such a way that Federal or state requirements are fulfilled. In 2015 the National Electoral Institute of Mexico carried out the redistricting process of 15 states using a nonlinear programming model where population equality and compactness were considered as conflicting objective functions, whereas other criteria, such as contiguity, were included as constraints. In order to find high quality redistricting plans in acceptable amounts of time, two automated redistricting algorithms were designed: a Simulated Annealing based algorithm, and an Artificial Bee Colony inspired algorithm. Computational results prove that the population based technique is more robust than its counterpart for this kind of problems.