An Adversarial Approach to Structural Estimation
Tetsuya Kaji, Elena Manresa, Guillaume Pouliot
TL;DR
The paper introduces adversarial estimation, a GAN-inspired, simulation-based method for structural econometric models, casting parameter estimation as a minimax problem between a generator (the structural model) and a discriminator (a classifier distinguishing real versus simulated data). By using a cross-entropy objective and a sufficiently rich discriminator, the estimator achieves parametric efficiency under correct specification and the parametric rate under misspecification, bridging simulated method of moments and maximum likelihood. The authors demonstrate the method on simple models (logistic location and Roy model) and on a substantive empirical application—elderly saving motives—showing that bequest motives matter across wealth levels and that the approach yields tighter inference than traditional SMM. They also discuss practical challenges, including computational cost, loss-surface roughness with neural discriminators, and the role of discrimination richness for efficiency, offering guidance on implementation and bootstrap-based variance estimation. Overall, adversarial estimation provides a flexible, efficient alternative for complex structural models where likelihoods are intractable but simulation is feasible, with direct applicability to policy-relevant questions like saving behavior in retirement.
Abstract
We propose a new simulation-based estimation method, adversarial estimation, for structural models. The estimator is formulated as the solution to a minimax problem between a generator (which generates simulated observations using the structural model) and a discriminator (which classifies whether an observation is simulated). The discriminator maximizes the accuracy of its classification while the generator minimizes it. We show that, with a sufficiently rich discriminator, the adversarial estimator attains parametric efficiency under correct specification and the parametric rate under misspecification. We advocate the use of a neural network as a discriminator that can exploit adaptivity properties and attain fast rates of convergence. We apply our method to the elderly's saving decision model and show that our estimator uncovers the bequest motive as an important source of saving across the wealth distribution, not only for the rich.
