The dual purpose of this project was to contribute to basic knowledge about the interaction between regulation and innovation and to inform the cost and benefit expectations related to technical change which are embedded in the rulemaking process of an important area of national regulation. The area of regulation focused on here is minimum efficiency performance standards (MEPS) for appliances and other energy-using products. Relevant both to U.S. climate policy and energy policy for buildings, MEPS remove certain product models from the market that do not meet specified efficiency thresholds.This project took the form of a retrospective review of regulation, which is a type of detailed case study that compares data on ex ante (i.e., before regulation) expectations about regulation to ex post (i.e., after regulation) observations of regulatory performance so that empirical evidence can guide future rulemaking decisions. This project differs from other retrospective reviews, however, in its focus on regulatory expectations and post-regulatory outcomes of technical change, which is a particularly important factor in the performance of MEPS, as it is in other areas of regulation. It also differs from other retrospective reviews in its focus on five products with different regulatory histories, namely room air conditioners, refrigerator-freezers, dishwashers, clothes washers, and clothes dryers. These five products, which heavily saturate U.S. households and are manufactured in a highly concentrated industry sector, are the full set of large household appliances which were subject to federal MEPS informed by rulemaking analyses conducted by the Department of Energy (DOE) from 1990 to 2012. The research advantages of focusing on these appliances in this time period include limiting selection bias, ensuring the likelihood of sufficient data for retrospective review, and limiting variation in product markets. Finally, this project differs from other retrospective reviews in the scope of data employed. Ex ante data included rulemaking analyses and other documents in the regulatory docket. Ex post data included rich, often high resolution data covering several aspects of product price, quality, and design: (1) extensive 2003-2011 U.S. point-of-sale data on appliance models matched to model energy use data (for all but clothes dryers) which facilitated construction of a monthly panel of model-specific prices, quality characteristics, and market shares; (2) authorconstructed datasets from independent third party appliance testing and product reliability surveys; and (3) an author-constructed dataset of the features identified in the product manuals of 1,109 clothes washer models sold in the U.S. in 2003-11 (these models represented 95% of the identifiable models in the point-of-sale data, which account for 29% of U.S. units sold over that period).At least seven questions were addressed in this project, which cluster around considerations of whether and how product price, quality, and design changed after regulation...