A Patent Analysis of Global Food and Beverage Firms: The Persistence of Innovation Oscar Alfranca Universitat Politècnica de Catalunya, ESAB, Urgell, 187, 08036 Barcelona, Spain. E-mail: oscar.alfranca@upc.es Ruth Rama Instituto de Economía y Geografía, Consejo Superior de Investigaciones Científicas (CSIC), Pinar, 25, 28006 Madrid, Spain. E-mail: rrama@ieg.csic.es Nicholas von Tunzelmann SPRU (Science and Technology Policy Research), University of Sussex, Brighton, United Kingdom ABSTRACT We explore whether current innovation has an enduring effect on future innovative activity in large, global food and beverage ~ F&B! companies+ We analyze a sample of 16,698 patents granted in the United States over the period 1977 to 1994 to 103 F&B firms selected from the world’s largest F&B multinationals+ We test whether patent time series are trend stationary or difference stationary in order to detect how large the autoregressive parameter is and how enduring the impact of past innovation in these companies is+ We conclude that the patent series are not consistent with the random walk model+ The null hypothesis of a unit root can be rejected at the 5% level when a constant and a time trend are considered+ Both utility and design patent series are stationary around a constant and a time trend+ Moreover, there is a permanent component in the patent time series+ Thus, global F&B firms show a stable pattern of technological accumulation in which “success breeds success+” “Old” innovators are the ones to foster both important changes and new ways of packaging products among F&B multinationals+ The effect of past innovation is almost permanent+ By contrast, other potential stimuli to technological change have only transitory effects on innova- tion+ Patterns of technological accumulation vary in specific F&B industries+ Past experience in design is important in highly processed foods and beverages, but not in agribusinesses and basic foodstuffs+ Patterns of technological accumulation are similar in both smaller multinationals 0 newcomers and large, established multinationals+ @EconLit citations : O330, F230, L660# © 2002 Wiley Periodicals, Inc+ 1. INTRODUCTION The work of evolutionary ~or neo-Schumpeterian! economists points strongly to the ac- cumulative nature of technology ~for a survey , see Freeman, 1994!+ This strand of theory shows the importance of both incremental and radical innovation+ As stressed by Free- man ~1994, p+ 473!, neo-Schumpeterians claim that the accumulation of knowledge is firm specific, as in Penrose ~1959!+ Not only is the acquisition of problem-solving capa- Agribusiness, Vol. 18 (3) 349–368 (2002) © 2002 Wiley Periodicals, Inc. Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/agr.10021 349