“…Here, q is called the retention level of the insurer, which is obviously valued in [0, 1]. To the best of our knowledge, in most of existing literature, it is usually assumed that q ∈ [0, ∞) and the case of q ∈ (1, ∞) is interpreted as acquiring new business, see [2], [23], [37], [31] and [33], etc. However, this assumption of acquiring new business is too strong, since it implies that original/old and new businesses are the same and the premium rate of new business and that of the reinsurance are also the same.…”