Develop a stochastic MPEC variant for online BLP estimation

Develop a stochastic mathematical-programming-with-equilibrium-constraints (MPEC) variant of the BLP estimation procedure within an online framework, incorporating the inner demand-inversion fixed point as a constraint in sequential parameter updates.

Background

The paper’s stochastic nested fixed point (SNFP) algorithm processes one market at a time and solves the BLP contraction mapping locally within each stochastic-gradient update. This substantially reduces the memory and computational burden of conventional full-sample nested fixed point estimation, but it retains the demand inversion as an inner iterative procedure.

The authors identify an online stochastic MPEC formulation as a related unresolved methodological extension. Such a method would embed the inner BLP fixed-point problem directly into constraints in an online estimation framework, potentially combining the computational advantages of MPEC with sequential market-by-market updating. The paper does not develop or analyze this variant.

References

Finally, building on the MPEC formulation for BLP \citep{dube2012improving} (and subsequent practical guidance in \citet{conlon2020best}), it would be natural to develop a stochastic MPEC variant within an online framework, which we leave to future work.

— A Stochastic Nested Fixed Point Algorithm for Large-Scale BLP Estimation  (2609.23998 - Lu et al., 21 Sep 2026) in Section 3, immediately following Algorithm 1 (SNFP), in the concluding remarks of the algorithm section