Studies on simulation input uncertainty often built on the availability of input data. In this paper, we investigate an inverse problem where, given only the availability of output data, we nonparametrically calibrate the input models and other related performance measures of interest. We propose an optimization-based framework to compute statistically valid bounds on input quantities. The framework utilizes constraints that connect the statistical information of the real-world outputs with the input-output relation via a simulable map. We analyze the statistical guarantees of this approach from the view of data-driven robust optimization, and show how the guarantees relate to the function complexity of the constraints arising in our framework.We investigate an iterative procedure based on a stochastic quadratic penalty method to approximately solve the resulting optimization. We conduct numerical experiments to demonstrate our performance in bounding the input models and related quantities. Daley D, Servi L (1998) Moment estimation of customer loss rates from transactional data. International Journal of Stochastic Analysis 11(3):301-310. Dang CD, Lan G (2015) Stochastic block mirror descent methods for nonsmooth and stochastic optimization. SIAM Journal on Optimization 25(2):856-881. Delage E, Ye Y (2010) Distributionally robust optimization under moment uncertainty with application to data-driven problems. Operations Research 58(3):595-612. Donoho DL, Johnstone IM, Hoch JC, Stern AS (1992) Maximum entropy and the nearly black object. Journal of the Royal Statistical Society. Series B (Methodological) 41-81. Duchi J, Glynn P, Namkoong H (2016) Statistics of robust optimization: A generalized empirical likelihood approach. arXiv preprint arXiv:1610.03425 . Durrett R (2010) Probability: Theory and Examples (Cambridge university press). Esfahani PM, Kuhn D (2015) Data-driven distributionally robust optimization using the wasserstein metric: Performance guarantees and tractable reformulations. arXiv preprint arXiv:1505.05116 . Fan W, Hong LJ, Zhang X (2013) Robust selection of the best. Gao R, Kleywegt AJ (2016) Distributionally robust stochastic optimization with wasserstein distance. arXiv preprint arXiv:1604.02199 . Ghadimi S, Lan G (2013) Stochastic first-and zeroth-order methods for nonconvex stochastic programming. SIAM Journal on Optimization 23(4):2341-2368. Ghadimi S, Lan G (2015) Accelerated gradient methods for nonconvex nonlinear and stochastic programming. Mathematical Programming 1-41. Ghadimi S, Lan G, Zhang H (2016) Mini-batch stochastic approximation methods for nonconvex stochastic composite optimization. Mathematical Programming 155(1-2):267-305. Ghosh S, Lam H (2015a) Computing worst-case input models in stochastic simulation. Available at http://arxiv.org/pdf/1507.05609v1.pdf . Ghosh S, Lam H (2015b) Mirror descent stochastic approximation for computing worst-case stochastic input models. Proceedings of the 2015 Winter Simulation Conference, 425-436 (IEEE Press). 35 Ghosh S, Lam H (2015c) Robust...