Module XI·Article IV·~1 min read
Practice of Welfare Analysis
Surplus and Welfare
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Practice of welfare analysis — Welfare analysis is a practical tool for evaluating policies and changes. How do we apply surplus concepts to real-world issues?
Cost-Benefit Analysis
Principle: a policy/project is justified if benefits > costs.
Measurement of benefits:
- Change in CS
- Change in PS
- Change in government revenues
Measurement of costs:
- Direct expenditures
- DWL
- Opportunity costs
Example: assessment of a tariff
Introduction of an import tariff:
- Domestic price rises
- CS falls (consumers pay more)
- PS rises (domestic producers receive more)
- Government receives tariff revenues
- DWL: from reduced consumption + from inefficient production
Result: usually ΔCS > ΔPS + tariff revenue. Net loss = DWL.
Consideration of distribution
Weighted welfare: different weights for different groups.
Compensating/Equivalent Variation:
- CV: how much needs to be compensated after the change
- EV: how much one is willing to pay to avoid the change
Political decisions: welfare analysis informs, but does not determine — value judgments are inevitable.
Limitations
Measurement: willingness to pay depends on income. The poor "value" less in monetary terms.
Comparison between people: cannot directly compare utility.
Not accounted for:
- Dynamics and long-term effects
- Uncertainty
- Behavioral effects
For the investor
Policy analysis: assessment of the impact of regulatory changes on industries and companies.
M&A analysis: who gains, who loses from the deal.
Stakeholder mapping: understanding the interests of different groups.
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