Foreword In April1971, Los Angeles and its satellite cities were treated to one of its least interesting and least publicized elections in years. Nothing seemed to be hotly contested. A few Los Angeles city councilmen were up for reelection as were some members of the Board of Ed ucation and the Board of Trustees of the Community Colleges. - Nakanishi, Cooper and Kassarjian [1974] Our colleague, Professor Harold H. Kassarjian, ran for one of the seats on the Board of Trustees and received 17,286 votes. While he lost the election, he had collected the data which he felt characterized voting in such /ow-invo/vement cases. He asked us to join him in writing a follow-up to a study of a similar election which had been published the previous faU in Public Opinion Quarter/y. Neither of us was content with the methods and models used in the prior study. Shares are different than other criteria, be they vote shares, market shares or retail stores' shares of customers. Different methods are needed to reflect their special nature. And thus began a research collaboration, running 17 years, so far. Though our combined research efforts have covered diverse areas of consumer choice behavior, in recent years we carne to the realization that our models and analytical methods might be very profitably employed in the analysis of market-share figures for consumer products.