摘要：Climate change is one of the toughest challenges facing the world today. Putting a price on carbon emissions is an important step towards climate change mitigation. A cap and trade system is one of the ways to create a carbon price. The New Zealand Emissions Trading Scheme (NZETS) is the world’s first economy-wide cap and trade system that covers all sectors and all 6 greenhouse gases. Forestry is a major part of the NZETS, allowing foresters to earn carbon credits for new forests planted on and after 1st January 1990 (afforestation and reforestation). At the same time, the NZETS also makes foresters liable for harvesting new forests planted on and after 1st January 1990, and deforesting forests existing on and before 31st December 1989. In this paper, we perform an economic analysis of how a carbon price will likely affect the returns and forestry management behaviour in new forests in New Zealand. Previous works have used the NPV/LEV (fixed harvesting) analysis where the forest is assumed to be harvested (in future) at the estimated optimal rotation age regardless of timber prices at that time. Other works have employed the Real Options approaches (flexible harvesting) where sophisticated models such as Partial Differential Equations and simulations analyse the effects of bringing forward the harvest decision if timber prices are favourable, and deferring the harvest decision if timber prices are unfavourable. Often, these methods tend to have higher data requirements, employ different assumptions and are much more complex to estimate. Because of these differences, it may be difficult to compare the results of NPV/LEV analysis with Real Options. Our work here applies the binomial tree method, which is a relatively simple method that can generate both LEV (fixed harvesting) and Real Options (flexible harvesting) results on a common model with the same data requirements and assumptions. This allows for better comparability of forestry management behaviour and effects of carbon price. The forestry valuations are analysed under a stochastic timber price and a constant carbon price. This paper concludes with some implications on policy in New Zealand.
