1 Civil Systems Planning Benefit/Cost Analysis Scott Matthews Courses: and Lecture /22/2004
and Intro So far, we have considered externality problems in one of 2 ways: 1) By monetizing externality and including it explicitly as part of BCA 2) Finding cost, dividing by measured effectiveness (in non-monetary terms) While Option 2 is preferred, it is only relevant with a single effectiveness
and MAIS Table - Used for QALY Conversions Comprehensive Fatality / Injury Values Injury Severity1994 Relative Value MAIS MAIS MAIS MAIS MAIS Fatality1.0
and Single vs. Multiple Effectiveness Recall earlier examples: Cost per life saved Cost per ton of pollution When discussing “500 Interventions” paper, talked about environmental regs Had mortality and morbidity benefits Very common to have multiple benefits/effectiveness Under option 1 above, we would just multiply by $/life and $/injury values.. But recall that we prefer NOT to monetize and instead find CE/EC values to compare to others
and Multiple Effectiveness In Option 2, its not relevant to simply divide total costs (TC) by # deaths, # injuries, e.g. CE 1 = TC/death, CE 2 = TC/injury Why? Misrepresents costs of each effectiveness Instead, we need a method to allocate the costs (or to separate the benefits) so that we have CE ratios relevant to each effectiveness measure
and Options for Better Method Use “primary target” as effectiveness Allocate all costs to it (basically what we’ve been doing) Add effectiveness measures together E.g., tons of pollution Is as ridiculous as it sounds (tons not equal, lives not equal to injuries)
and Improved Method In absence of more information or knowing better, allocate costs evenly E.g., if 2 pollutants each gets 1/2 the cost Easy to make slight variations if new information or insight is available Could use our monetization values to inform this (e.g., external cost values, $/life values, etc.)
and Recall from previous lecture
and Another Option For each effectiveness, subtract marginal cost/benefit values of all other measures from total cost so that only remaining costs exist for CE ratios Again could use median $ values on previous slide to do this Examples..