THE SIGNIFICANCE OF DUMMY VARIABLES IN MULTIPLE REGRESSIONS INVOLVING FINANCIAL AND ECONOMIC DATA

IN A RECENT ARTICLE [4], Professor Ronald Wippern presented the results of several multiple regressions involving dummy variables. This note contains two criticisms of Wippern's published interpretation of these results. These criticisms detract little from Wippern's otherwise excellent article. Nonetheless, they seem worthwhile noting, since the use of dummy variables in multiple regressions is becoming widespread in the analysis of financial and economic data; therefore, the correct interpretation of such regression results is increasingly important. Wippern presents the following model as his equation (1):