Tobacco companies paid the Hollywood A-listers of the 1930s and 1940s millions of dollars in today's money to endorse particular brands of cigarette, under contract, reveals research in Tobacco Control.
The continued presence of on-screen smoking in today's mainstream films is rooted in these "studio era" deals, claim the authors.
The research team accessed cigarette endorsement contracts between tobacco companies and studio-controlled movie stars, as well as adverts of the period, from university and major US newspaper archives.
The period under investigation covered the years 1927 to 1951, from the advent of talking motion pictures to the rise of television.
In return for the paid testimonials of their stars in cigarette ads major studios benefited from nationwide print and radio ads for themselves and their movies in lucrative "cross over" deals, paid for by tobacco companies, shows the research.
The studios with the most "cross over" deals were Paramount and Warner Bros, with the peak of activity occurring in the early and late 1930s, particularly for Lucky Strike (American Tobacco) and in the 1940s for Chesterfield (Ligget & Myers).
This was despite previous attempts to curtail the practice.
In 1927 the Federal Trade Commission ruled against American Tobacco, prohibiting the use of testimonial endorsements, unless written by the endorser and providing "genuine, authorised, and unbiased" opinions.
And in 1931, the precursor to the Motion Picture Association of America, the MPPDA, banned actor endorsements and on-screen product placement.
But the archived material shows that the studios took advantage of their contracts, which gave them complete control over the use of their celebrities.
They were able to negotiate the content of the testimonials, and insist that the endorsement ads, publicising new movies, coincided with their release to cinemas.
In all, almost 200 actors took part in the cigarette endorsements, including two thirds of the top 50 box office Hollywood stars from the late 1930s through to the 1940s.
Among others, actors Clark Gable, Spencer Tracey, Joan Crawford, John Wayne, Bette Davis, Betty Grable and singer Al Jolson all appeared in endorsements for brands, such as Lucky Strike, Old Gold, Chesterfield, and Camel.
American Tobacco alone paid the stars who endorsed Lucky Strike cigarettes US$ 218,750 in the late 1930s, equivalent to $3.2 million in today's money.
Individual stars earned up to $5,000 per year, equivalent to around $75,000 in today's money.
And in 1946, Ligget & Myers spent the equivalent of $50 million advertising Hollywood, which was more than its brand endorsement partners Paramount, 20th Century Fox, Warner Bros and Columbia Pictures combined.
The authors say that smoking in movies is associated with teens and young adults starting to smoke themselves, but its persistent presence in mainstream films is rooted in the mutually beneficial deals between the film and tobacco industries in the 1930s and 1940s.