本文將處理交換理論中的一個核心議題：爲什麼不同的物品一特別是關於 人一可以被交換？寮國北部拉莫特（Rmeet,即Lamet)人在婚喪儀式的交換 中，交換物所呈現的關係是一種不完全的替代。在婚禮中，聘禮被當地人視爲是用 來「買」新娘的，但這二者其實並不等値——因爲給妻者會繼續提出更多的需索， 雖然同時也可能會提供嫁妝給討妻者。而在喪禮的犧牲祭祀中，就肉的分配方式而 言，所獻祭的水牛可說是等同於死者，但這樣的論點卻無法解釋，爲什麼水牛的頭 顱骨最後要被放置於墳上。
針對這些在交換中不同的可替代狀況——亦即「聘禮—新娘」以及「水牛—死者」——本文採取兩種模式進行分析：其一是透過第三項物的運用，讓交換物成爲 類似的東西(例如,水牛和人都具有的以klpu「靈魂」）；其二是採用交換物呈現對立、 卻同時也有互補價値的觀念來分析（例如，由新娘所具體化的「姻親關係」觀念， 以及聘禮所具體代表的「父系世系」觀念，二者皆爲繁衍的原則)。然而，這裡所 討論的毎一種交換關係中的特定價値或一方，其實都已具有其旣定的優勢，因此沒 有一個交換的結果是圓滿或可以達到平衡的。在拉莫特人的儀式性交換中，透過水 牛的頭顱骨和嫁妝等物，具體地顯現了這種不完全替代的特性，並象徵著被交換的 物或人及其替代物之間的差距。

This article addresses a central concern of exchange theory: why different objects, and specifically persons, can be exchanged. The relation between objects of exchange in the rituals of the Rmeet (Lamet) in Laos shows an incompleteness of replacement. Bride-prices are thought to “buy” the bride, but are not equivalent with her—wife-givers demand further payments over time, but they also may provide a dowry. During mortuary sacrifices，the meat of a buffalo is distributed in a way that suggests it is identified with the dead, but this raises the question why its skull is placed on the grave. Two models for conditions of replaceability—of brides by bride-price and the dead by buffaloes—are used in the analysis: (1) the employment of a third term that makes exchange objects similar (the klpu “soul” of both buffaloes and humans); and (2) the notion that the objects represent contrasting, but ultimately complementary values (affinity, embodied by the bride, and patrilineality, embodied by the bride-price, as reproductive principles). Still, each exchange relation in question is valorized, with one value or party being superior, therefore, no exchange can be complete and balanced. This incompleteness is manifest in signifiers like the skull and the dowry, which signify the gap between the object or person and its replacement.