(卫生经济学课件)CBA

• maximum WTP
= $50
• implied value of life
= 50/5 x 10-5
•
=$1m
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Global versus restricted WTP
• Three broad categories of benefits: intangible, future health care costs avoided and increased productive output.
• opportunity cost of time
• a replacement cost
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Revealed preference approach
• To examine the relationship between particular health risks associated with a hazardous job and wage rates that individuals require to accept the job.
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Answer to the WTP example
• current risk of death without safety feature = 10/100,000
• new risk with safety feature
= 5/100,000
• reduction in risk
= 5/100,000
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Difficulties of human capital approach
• In theory wage rates reflect the marginal productivity of a worker, but it may reflect inequities such as discrimination by race or gender.
• Utilisation of health care programme can be viewed as an investment in a person’s human capital.
• In measuring the pay-back on this investment the value of the healthy time produced can be quantified in terms of the person’s renewed or increased production in the market-place.
• CBA is broader in scope than CEA/CUA
– can compare programs within and between sectors of the economy to inform resource allocation decision
– can tell if the programme is worthwhile or not, but CEA/CUA cannot
• The weakness is that estimated values have varied widely and estimation seems to be context and jobspecific. In the real life, the choice of job is not only depended on the risk. Many factors confound the relationship between wage and health risk.
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Example of WTP for road safety
• Suppose that you are buying a particular make of car. You can, if you want, choose to have a new kind of safety feature fitted to the car at an extra cost. The next few questions will ask about how much extra you would be prepared to pay for some different types of safety feature. You must bear in mind how much you personally can afford. The risk of a car driver being killed in an accident is 10/100,000. You could choose to have a safety feature fitted to your car which would have the risk of the car driver being killed, down to 5/100,000. Taking into account how much you can personally afford, what is the most that you would be prepared to pay to have this safety feature fitted to the car?
• The strength is that it is based on actual consumer choices involving health versus money, rather than hypothetical scenarios and preference statements.
– To value all aspects of health improvements – To value part of the benefits of health care
interventions, using earnings data as a means of valuing productivity changes only.
(卫生经济学课件)CBA
Concept of CBA
• CBA compares the discounted future streams of program benefits with program costs.
• The goal of CBA is to identify whether the a program’s benefits exceed its costs.
• What is the implied value of statistical life?
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Answer to the example of revealed preference
• The implied value of statistical life is then $5 million for workers in job B who are each willing to forgo $500 per year for a 1/10,000 lower annual death risk.
• In many ways CBA studies based on contingent valuation and statement of WTP can be thought of as attempts to replace missing markets, in an attempt to measure underlying consumer demand and valuation for non-market social goods.
status
• These benefits can be measured by
– Human capital approach – revealed preferences – stated preferences of willingness-to-pay
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Human capital approach (1)
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Human capital approach (2)
• It places monetary weights on healthy time using market wage rates and the value of the program is assessed in terms of the present value of future earnings.
• A positive net social benefit indicates a program is worthwhile.
• In CBA, program consequences are valued in monetary units, becoming benefits.
2
Difference between CBA and CEA/CUA
• 500 x 10,000 = 5,000,000 = 5 million
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Stated preference approach (WTP)
• To use survey methods to present respondents with hypothetical scenarios about the program or problem under evaluation. Respondents are required to think about the scenarios and to reveal the maximum they would be willing to pay for the program or benefit.
• Benefits can be divided into
– intangible benefits which are the value of improved health
– future health care costs avoided – increased productive output due to improved health
– CEA/CUA address mainly questions of production efficiency, in contrast, CBA address both production efficiency and allocative efficiency
3
Measure of benefit
8Fra Baidu bibliotek
Example of revealed preference
• Suppose jobs A and B are identical except that workers in job A have higher annual fatal injury risks such that, on average, there is one more job-related death per year for every 10,000 workers in job A than job B, and workers in job A earn $500 more per year than those in job B.
• From a societal perspective the analyst would need to consider the value of healthy time gained that is not sold for a wage.
– Shadow price on non-marketed resources:
• Restricted WTP only value those component of benefit for which no money values existed from other market sources, thus only intangible (change in health).