本研究探討訊息不對稱下的產業內授權契約。本研究討論，如果只有被授權廠商擁有其授權後的成本訊息，而授權廠商沒有此訊息時，授權廠商的最適授權策略與授權契約。在此研究中我們得到：第一、授權廠商可能採取混合授權策略與單一授權策略，但只有在被授權廠商授權後邊際成本可能較授權廠商低時，授權廠商才可能會採取分離授權策略。第二、授權廠商採取混合授權策略時，必定以單位權利金進行授權，且此單位權利金會大於效率較差廠商邊際成本的降幅。第三、若授權後被授權廠商的邊際成本較授權廠商的邊際成本低，且授權廠商採取單一授權或分離授權策略，最適授權契約呈現多樣性。最適授權契約可能為單位權利金授權，兩階段定價授權，或固定權利金授權。這種契約的多樣性符合現實世界中的實際觀察，也修正了傳統產業內授權文獻中，單位權利金授權優於固定權利金授權的結論。

We examine the insider licensor's optimal licensing strategy and contract under asymmetric information, in which only the licensee owns the cost information post licensing while the licensor has no such information. We obtain the following results. Firstly, the insider licensor may choose to license to only one type of licensee and use the pooling licensing strategy, regardless of the relative marginal cost of the licensee post licensing to that of the licensor. However, the separating licensing strategy can only be used when the marginal cost of the licensee, post licensing, is smaller than that of the licensor. Secondly, when the licensor chooses the pooling licensing strategy, it must adopt a royalty licensing contract and the royalty rate will be greater than the amount of the reduction in the less efficient licensee's marginal cost. Lastly, provided that the licensee's marginal cost post licensing is smaller than that of the licensor and that the licensor chooses to license to only one type of licensee or use the separating licensing strategy, the optimal licensing contract can be royalty, two-part tariff or fixed-fee licensing. The diversity of the optimal licensing contract derived in this paper is consistent with observations in the real world, and is sharply different from the conventional result in which royalty licensing is always superior to fixed-fee licensing for an insider licensor.