Data Envelopment Analysis (DEA) is proposed as a method for measuring the efficiency of presidential campaigns. Campaign efficiency is defined as the success of incumbent party candidates in converting the economic conditions and presidential popularity of July into actual votes in November. DEA is described and illustrated using a case study (US presidential elections 1948-1996). Differences between outcome and efficiency and reasons for inefficiencies are explored. (C) 1999 Elsevier Science Ltd. All rights reserved.