This course covers methods and applications in economic theory. The focus is on structural econometric methods that are at the core of Empirical Industrial Organization. It emphasizes the interactions between economic theory and empirical methods rather than focusing just on statistical analysis. The class is divided into two parts. The first part covers estimation of demand functions and static oligopoly models. The second part studies static two-period models using a revealed preference approach, which normally leads to moment inequalities and to partial identification. This class also discusses some of the econometrics problems related to moment inequalities estimators.