Among the Writers Guild‘s 12,000 members are television writer-producers like Shonda Rhimes, the creator of “Grey’s Anatomy” and “Private Practice,” who take home up to $5 million a year. On the other extreme are junior writers who — if they work at all — make $50,000 or less. About 48 percent of West Coast members are unemployed, according to guild statistics. (No such statistics exist for East Coast members.) The economic disparity within the Writers Guild complicates the union’s job as it seeks increases in residual payments for the use of movies and TV shows on DVDs and online, among other issues. Brooks Barnes reports.