The Value of State Dependent Control in Ridesharing Systems
Published 2018-03-13Version 1
We study the design of state-dependent control for a closed queueing network model of ridesharing systems. We focus on the dispatch policy, where the platform can choose which vehicle to assign when a customer request comes in, and assume that this is the exclusive control lever available. The vehicle once again becomes available at the destination after dropping the customer. We consider the proportion of dropped demand in steady state as the performance measure. We propose a family of simple and explicit state-dependent policies called Scaled MaxWeight (SMW) policies and prove that under the complete resource pooling (CRP) condition (analogous to the condition in Hall's marriage theorem), each SMW policy leads to exponential decay of demand-dropping probability as the number of vehicles scales to infinity. We further show that there is an SMW policy that achieves the optimal exponent among all dispatch policies, and analytically specify this policy in terms of the customer request arrival rates for all source-destination pairs. The optimal SMW policy protects structurally under-supplied locations.