The female advantage of many gynodioecious species has been quantified (as the ratio between male-sterile's female fitness and hermaphrodites' female fitness) and is mostly comprised between 1 and 2.
Studies have quantified the advantage females possess in species with gynodioecy, which is expressed as a ratio comparing the fitness of female-sterile individuals to hermaphroditic females.  This ratio generally falls between 1 and 2.