Davis DR, DeSarno MJ, Bergeria CL, et al. - Given an increase in cigarette preference as a function of greater nicotine content, but, preference can be shifted via manipulating cost. In the present study, researchers sought to model if (1) preference shifts could be related with the behavioral-economic metric unit price (cost/reinforcer magnitude) and (2) if a link exists between preference shifts toward reduced nicotine contentand smoking reductions. From vulnerable populations, 169 daily smokers completed two concurrent-choice conditions examining preference for smoking normal (15.8 mg/g) and reduced (0.4 mg/g) nicotine content cigarettes in a multisite study between 2015 and 2016. In Condition 1, there was the availability of both products at 10 responses/choice. In Condition 2, the 0.4 mg/g dose remained available at 10 responses/choice while the availability of 15.8 mg/g dose was made on a progressive-ratio (PR) schedule wherein response cost increased following each choice. In Condition 1, the 15.8 mg/g dose was preferred by participants over 0.4 mg/g dose, but in Condition 2, their preference shifted to the 0.4 mg/g dose immediately before the point in the PR progression where the unit price for 15.8 dose exceeded the unit price for the 0.4 dose. Findings thereby suggest the role of the unit price of nicotine in cigarette product preference and thus it may provide a metric for prophesying preference and potentially influencing it through tobacco regulations. Further, they observed sustained lower smoking rates in correlation with reduced compared with normal nicotine content cigarettes; this was observed even under acute laboratory conditions and in vulnerable populations.