The inclusion of Harvested Wood Products (HWP) in the ETS would provide a modest increase in the profitability of growing trees for carbon units as well as timber, particularly if HWP that are exported are included. The inclusion of HWP does not change optimum rotation lengths to any great extent. The greatest impact would be to reduce carbon price risk to the forest grower by (a) extending the period after harvesting over which units must be surrendered; and (b) reducing the number of units that must be surrendered, if harvesting is followed by replanting. Inclusion of HWP in international rules would substantially reduce the carbon deficit faced by New Zealand after 2020 because of the narrow age-class structure of the Kyoto-eligible forest estate.