Economic Impacts of Multiple Agro-Environmental Policies on New Zealand Land Use

This paper investigates the implications of policy on farm income, land use, and the environment when New Zealand landowners face multiple environmental constraints. It also looks at the interaction between climate and nutrient reduction policy and the extent to which one policy can be used to meet the other’s objectives. We use a non-linear, partial equilibrium mathematical programming model of New Zealand land use to assess the economic impacts of climate and water policies at the New Zealand territorial authority level. The spatially explicit agro-environmental economic model estimates changes in land use, agricultural output, land management, and environmental impacts. The policies investigated include a range of carbon prices on land-based emissions ($0–30/tCO\(_{2\mathrm{e}}\)) as well a range of prices on nitrogen leaching from diffuse sources ($0–30/kgN). We estimate that implementing stand-alone greenhouse gas and nutrient emissions reduction policies for the agricultural and forestry sectors will create environmental benefits outside the scope of the policy. However, not all environmental outputs improve, and net farm revenue declines by between 0 and 11%. Simultaneously implementing the two policies results in the desired goals of reductions in nitrogen and greenhouse gas emissions with a marginal economic burden on landowners (i.e. 1–2% additional loss in farm profit relative to a stand-alone policy).