Table 5

Qualitative uncertainty characterization for demand-side management health benefits model, focusing on key model assumptions.

Model Component

Model Assumption

Likely Magnitude of Uncertainty

Effect of Alternative Assumptions

Energy model

Insulation retrofits viable in 63% of homes, uniformly distributed nationally

small

-

Use of regression model to estimate REM/Design outputs

small

-

Calibration of regression model outputs to RECS data

small

-

Emissions reductions

All marginal power plants equally likely to be affected by change in electricity consumption

medium

Capacity- or availability-based allocation (↑)

Use of AP-42 emissions data for residential fuel combustion

medium

-

Constant emissions from power plants and residential fuel combustion over time

medium

Emissions decrease over time given regulations (↓)

Focus on air emissions of PM, NOx, SO₂

small

Include other criteria pollutants, air toxics (↑)

Intake fractions

Use of regression model estimates for intake fractions for power plants

unknown

-

Use of regression model estimates for primary PM intake fractions for residential combustion

large

Apply dispersion model with more refined spatial resolution (↑)

Use of regression model estimates for secondary PM intake fractions for residential combustion

unknown

-

Health evidence

Use of American Cancer Society cohort evidence to estimate mortality risks from PM

large

Use results from Six Cities Study (↑); use only time-series evidence (↓)

Equal toxicity of all particles

large

-

Linear concentration-response function with no threshold

unknown

Assume threshold at PM_2.5 annual NAAQS (↓)

Inclusion of only asthma attacks, restricted activity days for morbidity

medium

Incorporate other morbidity outcomes (↑)

Valuation

Use of VSL of $6 million for mortality

large

-

Constant real price of fuel over time

small

-

Model framework

Focus only on public health

medium

Include greenhouse gases, dependence on oil imports, etc. (↑)

Focus only on emissions reductions from energy savings

medium

Include emissions from insulation manufacturing, occupational risks, indoor air quality, etc. (↓)

Note: ↓ indicates that alternative assumption would likely reduce the net benefit estimate; ↑ indicates that alternative assumption would likely increase the net benefit estimate

Levy et al. Environmental Health: A Global Access Science Source 2003 2:4   doi:10.1186/1476-069X-2-4