2. Non-smoking: Respondents are assigned a value of 1 at each interview if they report not using tobacco products at all in the last 30 days.
3. Eating breakfast: The Add Health data do not provide consistent measures of breakfast eating habits across all waves; however, I link two measures of eating breakfast together by assigning a value of 1 if respondents eat breakfast at all, and a value of 0 otherwise. At wave I, respondents were asked, ‘‘What do you usually have for breakfast on a weekday morning?’’ Individuals who reported having something for breakfast other than coffee, tea, or ‘nothing’ received a score of 1. At waves II and III, respondents were asked how many days in the last week they ate breakfast. Those who reported eating breakfast at least one day of the week received a score of 1.