RESUMO
Pictorial health warnings (PHW) were introduced in Mexico by the end of 2010. Different studies have assessed how PHW influence attitude or desire to renounce smoking, but they have not studied the actual effect on the demand of tobacco products. Our objective in this paper is to analyze the effect of duration of pictorial health warnings on consumption of tobacco in Mexico. We assess the influence of different consecutive rounds of pictorial warnings, taking into account their length and the use of repeated images. We use a Dynamic Least Squares model (DOLS) with quarterly data (1994-2015), to estimate the long run demand of cigarettes in Mexico, as a function of per-capita income, the relative price of tobacco, different regulatory measures and the different rounds of pictograms, its duration, and the use of repeated images. We find evidence indicating that the pictorial health warnings have reduced consumption of cigarettes, that the effect has decreased in the last rounds, and that the most effective duration of the rounds is six months. PHW regulation deters consumption; however, its effectiveness decreases over time, suggesting that consumers tend to adapt to images.