While the proportion of daily smokers in Norway more than halved between 1973 (42 per cent) and 2011 (17 per cent), the proportion of occasional smokers remained more or less constant within an 8 to 13 per cent band in the same period. The lowest percentages were recorded in the '70s and '80s, the highest in the mid '90s, though figures declined again in the early 2000s. Over the last two to three years, however, the percentage of occasional smokers increased slightly, recording 11 per cent in 2011 (ssb.no). Since variations in the proportion of non-daily smokers are small, however, it can be said to be a reasonably stable figure.
Occasional smokers differ from daily smokers partly because they tend not to see themselves as smokers and partly because they are more likely to have higher educational achievements than daily smokers. Having said that, intermittent smoking may cause nicotine addiction and encourage a habit of daily smoking. We know very little about the factors that dispose a person to become an intermittent smoker, that effect whether intermittent smoking is a stable behaviour and whether intermittent smokers are more likely to stop smoking or turn into daily smokers.
Using pre-collected data on smoking behaviour over time, on the educational achievements of parents and the smokers themselves, as well as smokers' school achievements (these data come from the longitudinal study Young in Norway conducted by Norwegian Social Research - NOVA), it should be possible, for example, to establish whether intermittent smoking is a stable behaviour (tracking), whether intermittent smoking is a risk factor for nicotine dependence, and determine the relative importance of factors in childhood, such as parents' educational level and smokers' own achievements at school, for pre-disposing individuals to become occasional smokers.