市場の失敗
Market Failure / マーケット・フェイラー
Market failure helps decide regulation or intervention by clarifying welfare losses and the trade-offs between efficiency and intervention costs. It keeps scope and assumptions aligned.
Market failure occurs when markets do not allocate resources efficiently due to externalities, market power, information asymmetry, or public goods. It specifies the unit of analysis and the assumptions behind welfare losses, including competitive conditions and information availability. The concept separates what is in scope (externalities, monopoly power, and information gaps) from what is out of scope (normal price fluctuations), so comparisons stay consistent. Applied well, it turns a vague debate into a measurable choice and makes the drivers of results explicit.
Use Market Failure analysis to decide regulation or intervention, because it exposes welfare losses and the trade-off with efficiency versus intervention costs. It changes budgeting and prioritization by making competitive conditions and information gaps explicit and reviewable. It informs adjustments when technology or regulation changes, so the decision stays grounded in current conditions.
- Use Market Failure analysis to decide regulation or intervention, because it exposes welfare losses and the trade-off with efficiency versus intervention costs.
- It changes budgeting and prioritization by making competitive conditions and information gaps explicit and reviewable.
- It informs adjustments when technology or regulation changes, so the decision stays grounded in current conditions.
- Define the unit and time horizon before comparing welfare losses across options.
- Track the primary driver (welfare loss) separately from secondary noise.
- Run sensitivity checks on elasticities and enforcement costs to avoid false precision.
- Document data sources and calculation steps so results are auditable.
- Revisit the analysis when the business model or market context changes.
Regulators assess a market with high switching costs and data lock-in. They quantify welfare loss using price markups and reduced entry, then compare light-touch disclosure rules versus stronger interoperability requirements. The analysis indicates interoperability would reduce market power with limited cost. After implementation, they monitor prices and entry to see if the failure narrows.
Compare Market Failure with adjacent concepts before deciding. Market Failure | Current concept | Use when the team needs the primary decision lens Adjacent metric or framework | Supporting lens | Use when the team needs evidence or process detail General vocabulary | Broad explanation | Use only for orientation, not final decision-making
| Metric | Difference | Why read together |
|---|---|---|
| Market Failure | Current concept | Use when the team needs the primary decision lens |
| Adjacent metric or framework | Supporting lens | Use when the team needs evidence or process detail |
| General vocabulary | Broad explanation | Use only for orientation, not final decision-making |
- Market failure does not imply markets are always bad; it signals specific frictions.
- Intervention can also fail and must be evaluated.
- Evidence is required to diagnose market failure correctly.
When should I use Market Failure?
Use it when the team needs to decide scope, priority, owner, or trade-off, not when it only needs a short definition.
What makes Market Failure useful in practice?
It becomes useful when it is tied to evidence, a decision owner, and a concrete next operating choice.
What should I avoid?
Avoid using the term as a label without clarifying assumptions, boundaries, and how success will be judged.