['To test the hypothesis that tobacco industry campaign contributions are influencing the behavior of members of the California legislature.', "Multivariate simultaneous-equations regression was used to analyze data on campaign contributions from the tobacco industry to members of the California legislature in 1991 and 1992, members' tobacco control policy positions, and members' personal characteristics.", "The following sources were analyzed: campaign contributions from disclosure statements filed with the California Fair Political Practices Commission; constituent attitudes on tobacco control from the California Tobacco Survey; legislators' personal characteristics, from a survey of key informants conducted by the California Journal; and the tobacco policy score, a survey of key informants working on tobacco issues in the state legislature. Specific voting on tobacco-related bills was also analyzed.", 'California legislature in 1991 and 1992.', 'All members of the California legislature in 1991 and 1992.', 'Tobacco policy score, campaign contributions, and votes on individual tobacco-related bills.', "The tobacco industry is having a statistically detectable effect on behavior of members of the California legislature on tobacco policymaking. On a scale of 0 to 10, a legislator's tobacco policy score dropped (ie, became more protobacco industry) by -0.11 for every $1000 in tobacco campaign contributions, after accounting for the fact that a more protobacco position was associated with greater contributions ($1855 for each -1.0 reduction in score). Members who were rated as effective received larger contributions from the industry. Members rated higher in integrity and intelligence were more antitobacco (higher scores) and Republicans more protobacco (lower scores) after taking into account the effects of contributions from the industry. Constituent attitudes were not reflected in legislators' perceived behavior."] Are tobacco industry campaign contributions affecting tobacco control policymaking in California?