摘要:Objectives . We evaluated the combined effects on California cigarette consumption of an additional 50¢ per pack state tax imposed by Proposition 10 of January 1999 and a 45¢ per pack increase in cigarette prices stemming from the Master Settlement Agreement (MSA) of November 1998. Methods . We used quarterly cigarette sales data for the period 1984–2002 to estimate a time-series intervention model adjusting for seasonal variations and time trend. Results . Over the period 1999 through 2002, the combined effect was to reduce cigarette consumption by 2.4 packs per capita per quarter (1.3 billion packs total over the 4-year period) and to raise state tax revenues by $2.1 billion. These effects were similar to the effects of a 25¢ per pack tax increase enacted by Proposition 99 a decade earlier, although with decreased relative effectiveness as measured by percentage of reduction in cigarette consumption divided by percentage of increase in taxation (−0.44 vs −0.60). Conclusions . A major increase in price through taxation and the MSA provided a strong economic disincentive for smokers in a state with a low smoking prevalence. This effect could be reinforced if part of the MSA payments were devoted to tobacco control programs. In November 1998, California voters passed Proposition 10, the California Children and Families First Act, increasing the state excise tax on cigarettes from 37¢ to 87¢ per pack beginning on January 1, 1999. All revenues raised by the additional tax were earmarked for early childhood development programs. This major increase in the state tax on cigarettes was not the first in California history. In November 1988, California passed Proposition 99, the Tobacco Tax and Health Promotion Act, an unprecedented antismoking ballot initiative that increased the cigarette tax by 25¢ per pack over the rate of 10¢ per pack that had been maintained since 1967. Proposition 99 became effective on January 1, 1989, and 20% of the new tax revenues was earmarked to fund a statewide tobacco control program that was launched in April 1990. In June 1993, the California Breast Cancer Act was passed, raising the cigarette tax by another 2¢ per pack, to 37¢, effective January 1, 1994. This additional revenue was intended to fund breast cancer research and early breast cancer detection services for uninsured and underinsured women. Several studies have examined the impact on California cigarette consumption of the 25¢ per pack tax increase following Proposition 99. Structural econometric analyses showed that following the implementation of Proposition 99, cigarette consumption was reduced by 8% to 10% in the short run and by 10% to 13% in the long run. 1 – 3 Time-series analysis indicated a 9% to 11% decline in cigarette sales after Proposition 99. 4 In addition, the antismoking media campaign funded by the earmarked excise tax revenues further reduced cigarette consumption. 5 , 6 A decade after the implementation of Proposition 99, the annual per capita cigarette consumption in California in 1998 had declined to 52.3 packs, which was 42% lower than its 1988 level of 90.1 packs and 39% lower than the 1998 national average of 85.8 packs 7 ; the adult smoking prevalence for California was 19.2% in 1998, among the 3 lowest US states. 8 Coinciding with the passage of Proposition 10, state attorneys general and the tobacco industry signed the landmark Master Settlement Agreement (MSA) on November 23, 1998. The MSA requires 4 major tobacco companies to pay 46 states and the District of Columbia a total of $206 billion over a 25-year period to reimburse the excess costs of treating smoking-related illnesses under Medicaid programs (the other 4 states had settled previously in June 1997). On the same day, the tobacco companies raised the wholesale price of cigarettes by 45¢ per pack, the largest increase in history, to finance their settlement costs. This price increase was expected to reduce cigarette consumption. Given the significantly lower level of cigarette consumption in California as of 1998, it is important for public health policymakers to investigate whether the additional 50¢ per pack tax increase imposed by Proposition 10 was an effective tobacco control strategy to further reduce cigarette consumption. In this study we intended to address this policy question. However, given that the implementation of Proposition 10 and the MSA happened almost at the same time, we sought to evaluate the combined effects of Proposition 10 and the MSA on California cigarette consumption by using quarterly cigarette consumption data in California. We then compared their effects to the effect of the tax increase raised by Proposition 99.