Non‐additivity in portfolios of exploration activities: a real options‐based analysis of equity alliances in biotechnology
研究了企业同时投资多个探索项目时，期权之间的相关性及投入可互换性如何导致组合价值出现次可加或超可加效应，并用生物技术行业数据验证了模型。
Abstract Firms invest in exploration‐oriented activities to seek competitive advantage and in response to changing environments. Real options formulations represent an emerging strand of thinking on such investments. In this paper we begin with the observation that firms often simultaneously invest in multiple exploration projects. We identify two sources of potential interactions among these real options investments. First, we investigate the effects of correlations between the outcomes in different options. Second, we analyze the effects of investments that are fungible across project options. We show that under different conditions multiple options can be sub‐additive (due to redundancies in outcomes) or super‐additive (due to fungible inputs). We test the implications of our model with data from the biotech industry and find supporting evidence. Our model and results have some interesting implications for the exploration literature and real options lens. Copyright © 2004 John Wiley & Sons, Ltd.