Abstract The current New Zealand Emissions Trading Scheme (ETS) allows forest growers to earn units under the stock change approach. Carbon price risk means that most participants are only trading safe units that they do not need to surrender after harvest provided that they replant. Consequently, the ETS has provided less incentive for afforestation than had been envisaged. This paper evaluates averaging as an alternative approach to carbon accounting. Two variations are considered: averaging based on nominated rotation age and averaging based on realised rotation age (i.e. carbon units are earned and sold up to the average for a base age of 28 years but carbon is only received up to the average for older ages after that age is attained). Both variations produce a higher Land Expectation Value (LEV) than that for the safe approach. Averaging with nominated rotation age has LEV within 90% of the carbon-stock change (i.e. sawtooth) approach but with much less risk. Averaging with realised rotation age has lower LEVs than averaging with nominated rotation age but has much less impact on optimum rotation age. Averaging provides the opportunity for all forest growers, regardless of area, to benefit from improved profitability under the ETS without taking on carbon price risk. Implementing the averaging approach in the ETS is forecast to lead to higher rates of afforestation than under the current ETS.

中文翻译：

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将新西兰排放交易计划改为平均方法对盈利能力、风险、最佳轮换年龄和植树造林的影响

摘要 当前的新西兰排放交易计划 (ETS) 允许森林种植者根据库存变化方法获得单位。碳价格风险意味着大多数参与者只交易安全的单位，他们不需要在收获后交出，只要他们重新种植。因此，ETS 对植树造林的激励低于预期。本文评估平均作为碳核算的替代方法。考虑了两种变化：基于指定轮换年龄的平均和基于已实​​现轮换年龄的平均（即碳单位的获得和销售最高为 28 年的基本年龄的平均值，但碳单位仅在 28到了那个年龄）。与安全方法相比，两种变化都会产生更高的土地期望值 (LEV)。指定轮换年龄的平均 LEV 在碳库变化（即锯齿）方法的 90% 以内，但风险要小得多。使用已实现的轮换年龄求平均值比用指定轮换年龄求平均值具有更低的 LEV，但对最佳轮换年龄的影响要小得多。平均为所有森林种植者提供了机会，无论区域如何，都可以从 ETS 下提高的盈利能力中受益，而无需承担碳价格风险。预计在 ETS 中实施平均方法将导致比当前 ETS 更高的造林率。平均为所有森林种植者提供了机会，无论区域如何，都可以从 ETS 下提高的盈利能力中受益，而无需承担碳价格风险。预计在 ETS 中实施平均方法将导致比当前 ETS 更高的造林率。平均为所有森林种植者提供了机会，无论区域如何，都可以从 ETS 提高的盈利能力中受益，而无需承担碳价格风险。预计在 ETS 中实施平均方法将导致比当前 ETS 更高的造林率。