  Since the introduction of electronic cigarettes to the United States market
in 2007, vaping prevalence has surged in both adult and adolescent populations.
E-cigarettes are advertised as a safer alternative to traditional cigarettes
and as a method of smoking cessation, but the U.S. government and health
professionals are concerned that e-cigarettes attract young non-smokers. Here,
we develop and analyze a dynamical systems model of competition between
traditional and electronic cigarettes for users. With this model, we predict
the change in smoking prevalence due to the introduction of vaping, and we
determine the conditions under which e-cigarettes present a net public health
benefit or harm to society.
