Gross planetary income was an economic indicator in use in the Ferengi Alliance. Grand Nagus Zek's 2374 amending of the Ferengi Bill of Opportunities to allow females to wear clothing was partly motivated by his frustration at their non-contribution to the gross planetary income. (DS9: "Profit and Lace") Gross planetary income is similar in name, and may therefore be similar in character, to Gross national income.