Ecological Economics Tiago Domingos Assistant Professor Environment and Energy Section Department of Mechanical Engineering Doctoral Program in Climate Change and Sustainable Development Policies Doctoral Program and Advanced Degree in Sustainable Energy Systems Doctoral Program in Mechanical Engineering Doctoral Program in Environmental Engineering

Multisector Optimal Growth m-dimensional consumption bundle, including everything that influences well-being. –Includes all non-market commodities, e.g, produced at home, environmental services, … n-dimensional capital vector: –Includes man-made capital, natural resources, human capital (education and knowledge) and foreign capital. Time is included as a capital, to depict technological progress in production. Attainable production possibilities The model s.t.

Criteria for Sustainability, Pezzey (2004) EDE An economy is sustainable at time t if and only if the representative agent’s current utility does not exceed the maximum level of utility which can be sustained forever from t onwards. One-sided sustainability test: un-sustainable development. Multisector results in real terms. –Real Net Income, –Genuine Saving, – Consumption Investment Variation in Real Net Income Variation in Welfare

Welfare Relationships Both Genuine Savings and Green NNI are related to future consumption. These relationships can be used to empirically check the theory. If genuine saving is negative (or green NNI deacreases) then current consumption will decrease in the future.

Small Open Economy Include –stocks of commercial forests, –welfare costs of air emissions, The capital stocks are : –Domestic man-made capital, –Net foreign capital held privately or by the government, –Stock of commercial natural resources Production r – interest rate

Small Open Economy Households’ utility function depends on material consumption rate and (negatively) on the flow of emissions The vector of emissions depends on production and abatement expenditure. Maximize welfare subject to the above relations and having as controls consumption,, all forms of extraction,, abatement expenditure and trade balance. Conventional (SNA) NNI: Green Net National Income: Genuine Saving (Adjusted Net Saving):

Small Open Economy – Table of symbols Consumption rate at time t Utility Rate of emissions of air pollutants Production function Abatement expenditure Extraction of natural resources for domestic use, exports and from imports. Imports - Exports Constant nominal interest rate Stock of resources Man-made capital, Resource price Constant real interest rate Cost of extraction of resource Marginal cost of abatement = Marginal damage cost Marginal cost of abatement Net foreign capital

Small Open Economy Starting from conventional SNA aggregates: –Deduct the damage from flow pollution emissions, –Deduct (add) the value of rents from resource depletion (or not),

Models point to measure emissions at the –Marginal cost of abatement (MCA), or –Marginal social cost (MSC) = Marginal benefit of abatement (MBA), a.k.a. Marginal Damage Costs (MDC) Measurement away from the optimum –c, over-polluting (assumed current state) => a is upper bound –d, under-polluting => b is lower bound Social costs vs Marginal abatement Constant MDC

GNNI and GS in Portugal – Air Emissions How to value a unit of emissions? –Marginal benefit of avoided emission, –Marginal cost of emission (MDC), or –Marginal abatement costs? Marginal cost of emission per emitted pollutant [€2000/ton]: [€2000/t] Best Low High SO NH NO x VOC PM2,

GNNI and GS in Portugal – Air Emissions

GNNI and GS in Portugal – Forests National Forest Inventory 2005/06 Average Volumes: Conifers Eucalyptus 95/9805/06 [m 3 /ha]

GNNI and GS in Portugal – Forests The depreciation of commercial forests in Portugal is on average 10% of the contribution of forestry to national product (around 4%).

GS in Portugal Without the value of time – Decreasing tendency throughout the period and negative GS after With the value of time – Decreasing tendency until 2001, but GS are always positive.

In 1993, SO2 costs of emissions, which represent around 30% of total emission costs, decreased substantially. Increases welfare but does not counteract the loss of production. Sustainability Message

What’s Missing? The depletion of water resources. The depletion of biodiversity. Depletion of stocks of fish. Inclusion of the value of ecosystem services. Soil quality. Distributional issues (intragenerational concerns)....