Devolution and the Union

Does not focusing the debate on the Barnett formula mean focusing it much too narrowly? If we are looking at expenditure, should we not look at the expenditure that the Barnett formula does not fully reflect? Should we not look at the income that the state receives, and the pooling and sharing of resources? If we are to have a review, let us look at the whole picture, rather than picking just one aspect of it.