Figure 2.

Five-compartment model of college drinking. All transfers are shown. Here N ₁, N ₂, N ₃, N ₄, and N ₅ and are the numbers of abstainers, light drinkers, moderate drinkers, problem drinkers, and heavy episodic drinkers, respectively, at time t. For convenience, we let Actual values for each parameter defining the transfer are also shown, including the range when the “wetness” parameter equals 0 (i.e., minimum [min]) and 1 (i.e., maximum [max]).