To determine Henkel's corporate beta, unlever (and relever) the ordinary least squares (OLS) market betas for each company in the European Household and Personal Care segment. Prices can be found on the "Prices" tab of the "Select Market Data" spreadsheet.
To determine the OLS market beta, regress 10-year monthly returns against the MSCI World index denominated in the same currency. In Excel, this can be done using the "SLOPE" formula.
Next, unlever the market beta using each company's year-end debt-to-equity ratio and the formula: bu = be/(1+D/E).
To determine Henkel's corporate beta, re-lever the average industry beta using Henkel's year-end debt-to-equity ratio.