組織生態學是從環境與組織的互動中來檢視組織行為，此派學者強調環境與組織 的合適性，是組織能夠持續存活的主因。組織生態學也從不同之觀點來定義市場競爭，其所 謂之市場競爭不同於媒介經濟學中直接面對面之競爭。就組織生態學而言，兩個組織或族群 只要有資源共享之情況出現，其已處在競爭之情況，因此，競爭並非皆是直接面對面之競爭 。本研究採用生態學中區位理論之觀點來檢視衛星電視對國內無線電視臺之影響。根據學者 Dimmick (1993) 之觀點， 電視產業中最重要的三種資源為廣告收入、閱聽眾及電視節目內 容。本研究以電視節目類型作為分析衛星電視對無線電視臺影響之基礎，運用區位理論分析 市場競爭之方式，研究發現：隨著市場競爭之加劇，內國三臺從過去寬區位之態勢，有漸漸 減少其區位寬度之現象。而家族頻道之經營已成目前電視產業之普遍現象。此外，本研究亦 發現，家族頻道數目與頻道之區位寬度成反比，也就是說，家族頻道數目愈多之頻道, 其區 位寬度愈窄。最後，區位重疊度之分析亦顯示，目前無線四臺與衛星電視的八個綜合臺正處 於競爭程度頗劇烈之情況，因為兩者之區位重疊度很大。

　　　　　Organizational ecology examines organizational behaviors by looking at the interaction between an organization and its environments. Organizational ecologists believe that the appropriateness between an organization and its environment is the main reason for the survival of this organization. Unlike media economists, organizational ecologists define market competition from a different perspective. According to organizational ecology, whenever there is overlapping between two organizations or two populations, they are in competition against each other. Therefore, competition is not always direct, nor is conscious. This study adopts the perspective of niche theory, which is one of the theories from organizational ecology, to analyze the impact of market competition on the terrestrial TV networks in Taiwan. According to Dimmick (1993), the most critical resources in TV industry are advertising income, audience, and program content. This study employed one of the three resources, program content, to examine the impacts of satellite TV on the terrestrial TV networks in Taiwan. Data analysis shows that as the market competition increases, the niches of the terrestrial TV networks become narrower, and that the degree of program overlapping between satellite TV and terrestrial TV is high, so the competition between them are strong. More findings are discussed in the paper.