This paper develops a systematic literature review about up- and down- alliances: vertical alliances (VAs) characterized by long term continuity between firms operating in adjacent stages of a value chain. Vertical alliances are a must for firms operating in a complex and unstable world, because they guarantee the advantages deriving from the vertical coordination of the value chain as well as the flexibility of cooperation.

In spite of the copious literature on alliances, few contributions focus specifically on VAs, so a clear overview of the phenomenon is missing. Furthermore, the different terminology and definitions found in the literature are confusing. Our systematic literature review identifies the theoretical approaches which are most used to study the development, potential and dynamics of VAs. The review highlights the main theories and the most explored topics, and identifies the gaps still existing in the literature. From the review, we developed a taxonomy to determine which research stream would be most congruent to a specific research topic.

本文对上下联盟进行了系统的文献综述：垂直联盟 (VA) 的特点是在价值链相邻阶段运营的公司之间具有长期连续性。对于在复杂和不稳定的世界中运营的公司来说，纵向联盟是必不可少的，因为它们保证了价值链纵向协调带来的优势以及合作的灵活性。

尽管有大量关于联盟的文献，但很少有人专门关注 VA，因此缺少对该现象的清晰概述。此外，文献中的不同术语和定义令人困惑。我们系统的文献综述确定了最常用于研究 VA 的发展、潜力和动态的理论方法。这篇综述突出了主要理论和探索最多的主题，并确定了文献中仍然存在的差距。通过审查，我们开发了一个分类法来确定哪个研究流最适合特定的研究主题。