We agree on the importance of contextual and temporal accuracy when studying novel tobacco products
We agree with Manderski et al that contextual and temporal accuracy is important when studying not just novel but all tobacco products, and carefully considered both issues that they raise in their comment when conducting our research.
As they acknowledged in their comment, 2009 is the closest year that National Youth Tobacco Survey (NYTS) data are available to the advent of e-cigarettes in the United States, which occurred around 2007. As they note, as of 2009, e-cigarette use was low and grew over time. We explicitly model this fact by quantifying this change with a slope (rather than an intercept) change in the regression model. (This is the approach shown in fig 2b of …