The cultural continuity is contingent, inessential. I think Anthony was slightly unfair to me in saying that I was only interested in how it came about and not in the practical implications. Now obviously it does matter to predict which nations will assert themselves, which potential nations, which cultural categories, will assert themselves and which will not. I would say it is inherent in the situation that you cannot tell. You can indicate certain factors.
Size is an obvious one, very small cultural groups give up.
Continuity is another one, but not an essential one. Some diasporic communities have very effectively asserted themselves. Size, continuity, existence of symbolism are important, but again the Estonians created nationalism ex nihilo in the course of the nineteenth century. I think Anthony was a little bit harsh on the economic determinists. When a cultural category is either systematically underprivileged in contrast with its cultural neighbours who may be territorially interspersed or on the contrary excites envy by advantages, that again provides motivation.