(a) Statistical studies. All statistical studies offered in evidence in hearing proceedings or relied upon as support for other evidence shall include a comprehensive description of the assumptions made, the study plan utilized, the procedures undertaken, and references from the academic literature supporting the procedures undertaken. Machine-readable data files, program files, workbooks, and all other necessary materials to enable independent replication of the results or program output if requested by the Commission or parties shall be provided in the form of a compact disk or other media or method approved in advance by the Secretary. Where a computer analysis is employed to obtain the result of a statistical study, all of the submissions required by paragraph (b) of this section shall be furnished, upon request. In addition, for each of the following types of statistical studies, the following information should be provided:
(1) Market research. The following information shall be provided:
- (i) A clear and detailed description of the sample, observational, and data preparation designs, including definitions of the target population, sampling frame, units of analysis, questionnaires or data collection instruments, survey variables, and the possible values;
- (ii) An explanation of methodology for the production and analysis of the major survey estimates and associated sampling errors;
- (iii) A presentation of response, coverage and editing rates, and any other potential sources of error associated with the survey's quality assurance procedures;
- (iv) A discussion of data comparability over time and with other data sources;
- (v) A complete description and assessment of the effects of all editing and imputation employed;
- (vi) Identification of all applicable statistical models considered and the reasons the model based procedures and/or models were selected over other models or procedures, when model-based procedures are employed; and
- (vii) An explanation of all statistical tests performed and an appropriate set of summary statistics summarizing the results of each test.
(2) Other sample surveys. The following information shall be provided:
- (i) A clear description of the survey design, including the definition of the universe under study, the sampling frame and units, and the validity and confidence limits that can be placed on major estimates; and
- (ii) An explanation of the method of selecting the sample and the characteristics measured or counted.
(3) Experimental analyses. The following information shall be provided:
- (i) A complete description of the experimental design, including a specification of the controlled conditions and how the controls were realized; and
- (ii) A complete description of the methods of making observations and the adjustments, if any, to observed data.
(4) Econometric studies. The following information shall be provided:
- (i) A presentation of the economic theory and assumptions underlying the study;
- (ii) A complete description of the econometric model(s) and the reasons for each major assumption and specification;
- (iii) The definition of the variables selected and the justification for their selection;
- (iv) For any alternative model whose computed econometric results influenced the choice of the preferred model, a statement of the reasons for rejecting that alternative, an identification of any differences between that alternative and the preferred model with respect to variable definitions, equation forms, data, or estimation methods, and, upon request, the computed econometric results for that alternative;
- (v) A reference to a detailed description in a text, manual, or technical journal for every econometric technique used in the estimation process and the reasons for selecting the technique, or, in the alternative, a description and analysis of the technique that is sufficient for a technical evaluation;
- (vi) Summary descriptions and source citations for all input data and, upon request, a complete listing of the data. Complete descriptions of any alterations, adjustments, or transformations made to the data as received from the original sources, and the reasons for making the alterations, adjustments, or transformations;
- (vii) A complete report of the econometric results including, where applicable coefficient estimates, standard errors and t-values, goodness-of-fit statistics, other appropriate test statistics, the variance/covariance matrix of the estimates, and computed residuals for results computed from samples composed of fewer than 250 observations, and, upon request, other computed residuals; and
- (viii) Descriptions of all statistical tests of hypotheses and the results of such tests.
(5) All other studies involving statistical methodology. The following information shall be provided:
- (i) The formula used for statistical estimates;
- (ii) The standard errors of each component estimated;
- (iii) Test statistics and the description of statistical tests and all related computations, and final results; and
- (iv) Summary descriptions of input data, and upon request the actual input data shall be made available at the offices of the Commission.