有關共有土地處分制度的問題，在國內民法第819條第2項及民法第828條第2項皆有所著墨，本研究聚焦於討論共有土地之處分問題，即於處分共有土地時，以全體成員同意之共決模式，此種模式運用在財產制度時，將導致在處分共有土地時，在共有人之間衍生出相當高的協商和決策成本，從而降低財產轉移之頻率。
本研究以法律經濟為導向觀點，針對現行土地法第34條之1所採取的共有土地處分之優先購買權制度，做成本效益分析，以「公平正義」和「經濟效益」兩大主軸為面向，分析目前制度所產生之交易成本，以建議一套符合[經濟效率之共有土地處分之優先購買權制度。
本研究主張必須賦予不同意處分之少數共有人，有關「財產法則」之優先購買權措施，於依土地法第34條之1第一項處分共有土地全部時，必須賦予優先購買權「物權」性質之效力，才能有效地降低交易成本，兼顧提昇「經濟效益」及追求「公平正義」，以利財產權制度之發展。
Regarding the issue of the common land disposal system, it is written in both the item 2 of article 819 and item 2 of article 828 under Taiwan civil law. This research mainly focuses on the issue of common land disposal, that is, when disposing of shared land, it shall be agreed by all members. This model applied to the property system will lead to the increase of high cost of negotiation and decision making. Thus, the frequency of property transaction will be reduced.
This study adopts the cost-benefit analysis on the preemptive right system for common land disposal adopted under the Article 34-1 of the Taiwan Land Law from the perspective of economic analysis of law. Based on the two main aspects of "fairness and justice" and "economic benefits," it analyzes the transaction cost raised in the current system in order to set up a set of preemptive right system meet the goal of economic efficiency.
This study argues that the minority co-owners who do not agree with the disposition must be granted the right of first refusal based on the "property rule". The preemptive right should be endowed with the effect of "real right" in order to effectively reduce transaction costs while the common land is disposal for the reduce of transaction cost effectively. Meanwhile it can balance the increase of “economic efficiency” and the pursuit of “justice and fairness” and benefit for the development of property right system.
