We have proposed a new usage-based account of variable case marking that explains these asymmetries between focus subjects and focus objects in case ellipsis in terms of the usage probability of properties of arguments, i.e., asymmetry in the frequency in which the argument accommodates new information.
it has been shown that both the degree of acceptability of case ellipsis on focused argument NPs in Korean and the strength of the influence of focus types on case ellipsis correlate with the likelihood for the argument's referent to be new information.