We present a unified look at myopic stability concepts for hedonic games, and discuss the status of the existence problems of stable coalition structures. In particular, we show that contractual strictly core stable coalition structures always exist, and present a sufficient condition for the existence of contractually Nash stable coalition structures on the class of separable games. Copyright Springer Science+Business Media, LLC 2007coalition formation, hedonic games, separability, taxonomy, C71, A14, D20,