So I just created a wiki article for the wide_hips tag, describing approximate waist/hip and shoulder/hip ratios for both males and females.

Since females generally have wider hips than shoulders, and males have wider shoulders than hips, here's what I came up with (these are all minimum values):

Male waist/hip: 0.9; shoulder/hip: 1.1
Female waist/hip: 0.7; shoulder/hip: 0.8

Let me know what you guys think of these guidelines, and if we should change them.