Resumen: This study evaluates the importance of product differentiation as a determinant of vertical integration in firms. The proposed model also controls for known determinants of integration, such as transaction costs and firm-level capabilities. By identifying transaction-, firm- and strategy-level determinants, we derive testable predictions about the vertical integration decision. To test these predictions we analyze the Rioja wine industry, using a representative sample of 187 firms. Our paper concludes that reaching judicious vertical integration decisions requires a thorough analysis of some very diverse aspects, especially those related to mitigating opportunism, dealing with unforeseen contingencies and product differentiation. Idioma: Inglés DOI: 10.3846/16111699.2013.815130 Año: 2016 Publicado en: Journal of Business Economics and Management 17, 5 (2016), 796-809 ISSN: 1611-1699 Factor impacto JCR: 0.968 (2016) Categ. JCR: ECONOMICS rank: 165 / 347 = 0.476 (2016) - Q2 - T2 Categ. JCR: BUSINESS rank: 100 / 121 = 0.826 (2016) - Q4 - T3 Factor impacto SCIMAGO: 0.283 - Business, Management and Accounting (miscellaneous) (Q2) - Economics and Econometrics (Q3)