@article {Barber:1985:0015-749X:73,
	author = "Barber, Richard L.",
	title = "The Aggregation of Age Classes in Timber Resources Scheduling Models: Its Effects and Bias",
	journal = "Forest Science",
	volume = "31",
	number = "1",
	year = "1985",
	abstract = "Efficient solution of resource scheduling problems usually requires aggregation of timber stands of many ages into a manageable number of discrete age classes, and that management actions such as harvest be represented as a single event occurring once each multiyear planning period. This can introduce two types of bias into solutions. One source of bias is related to the size of the age class interval and the other is related to the specific age within the interval to which harvest and inventory volume is attributed. In general, bias increases with aggregation interval. For yield and harvest estimation, bias is smallest if the yield is attributed to the oldest age in the interval rather than average age in the interval. Bias also increases for a given interval and age distribution assumption as the harvest rate diverges from the equilibrium rate. For present net worth computation, bias is appropriately handled by discounting equal annual payments over the interval period. Forest Sci. 31:73-82.",
	pages = "73-82",
	url = "http://www.ingentaconnect.com/content/saf/fs/1985/00000031/00000001/art00018",
	keyword = "Harvest scheduling, timber yield"
}