Cost-Benefit Analysis
The Cost-Benefit Analysis (CBA) module evaluates whether the economic benefits of a risk reduction intervention justify its implementation and maintenance costs.
CBA compares:
A Baseline scenario representing the existing risk condition.
An Alternative scenario representing a proposed mitigation, adaptation, or risk reduction measure.
The difference in Risk between the Baseline and Alternative scenarios represents the avoided loss, which is used as the economic benefit of the intervention. The CBA calculation then compares these benefits with the associated costs.
Overview
A CBA requires comparable Risk results for the Baseline and Alternative scenarios.
Examples of alternatives include:
Flood protection infrastructure.
Nature-based solutions.
Building retrofitting.
Early warning systems.
Land-use planning measures.
Other disaster risk reduction or climate adaptation interventions.
The CBA module calculates economic indicators that help users evaluate the economic performance of an intervention.
Required Inputs
Before starting a CBA calculation, ensure that the following are available:
Administrative Level
Baseline Risk result
Alternative Risk result
CBA Region
Economic parameters for the proposed intervention.
The Baseline and Alternative Risk results should represent comparable hazard and elements-at-risk combinations.
Instructions
Open the CBA Module
Go to the Project Page.
Click on the CBA tab in the sidebar.
Click Add CBA to begin.
Fill in General Information
In the General section, enter or select:
Name: provide a name for the CBA calculation.
Admin Level: select the administrative boundary layer.
Baseline Risk: select the Risk result representing existing conditions.
Alternative Risk: select the Risk result representing the proposed intervention.
CBA Region: select the area over which the CBA will be performed.
The CBA Region can be defined for the entire administrative region or for individual administrative units, depending on the available options.
Enter Economic Parameters
Enter the economic assumptions required for the CBA:
Base Year: reference year for the Risk results.
Project Starting Year: year in which the intervention begins.
Project Lifetime: duration of the economic evaluation.
Currency: monetary unit used for the calculation.
Total Investment Cost: initial cost required to implement the intervention.
Initial Investment Period: period over which the initial investment is implemented.
Annual Maintenance Cost: recurring cost required to maintain the intervention.
Discount Rate Percentage: rate used to convert future costs and benefits into present values.
Run the CBA Calculation
Review the selected Risk results and economic parameters.
Click Save & Next.
Complete the calculation.
Once the calculation is finished, the CBA results will be available for review.
CBA Calculation
The CBA calculation estimates the economic benefit of the intervention from the difference between Baseline and Alternative Risk.
Conceptually:
The resulting benefit represents the avoided loss associated with the intervention.
The platform then compares the benefits with the investment and maintenance costs over the project lifetime.
The calculation includes:
Annual costs.
Annual benefits.
Net benefits.
Discounted costs and benefits.
Economic performance indicators.
Results and Output
The CBA results are presented through Detail and Summary tables.
Detail Table
The Detail Table provides the year-by-year calculation throughout the project lifetime.
It allows users to observe:
Investment costs.
Maintenance costs.
Annual benefits or avoided losses.
Net benefits.
Discounted values.
The Detail Table can be used to understand how the costs and benefits develop over time.
Summary Table
The Summary Table provides the aggregated economic indicators for the CBA calculation.
Key indicators include:
Total Cost: total investment and maintenance costs.
Total Benefit: total avoided losses generated by the intervention.
Net Benefit: difference between total benefits and total costs.
Discounted Net Benefit: present value of the net benefits after applying the discount rate.
NPV: Net Present Value of the intervention.
BCR: Benefit-Cost Ratio.
IRR: Internal Rate of Return.
Payback Period: time required to recover the initial investment through accumulated benefits.
CBA Result Observation
The CBA results can be interpreted by comparing the economic benefits with the costs of the intervention.
Key indicators can be interpreted as follows:
Positive NPV: indicates that the intervention provides a positive economic value after discounting.
BCR greater than 1: indicates that the discounted benefits exceed the discounted costs.
Higher IRR: generally indicates a more economically attractive intervention.
Shorter Payback Period: indicates that the initial investment is recovered more quickly.
When comparing multiple alternatives, users should consider both economic performance and risk reduction. The alternative with the lowest cost is not necessarily the most beneficial if it also produces substantially lower avoided losses.
Note
CBA indicators should be interpreted together rather than relying on a single indicator. Economic results should also be considered alongside the magnitude of risk reduction achieved by the intervention.
Comparing Alternatives
RiskChanges can be used to compare multiple CBA alternatives.
Users can compare alternatives based on:
Total investment and maintenance costs.
Total avoided losses.
NPV.
BCR.
IRR.
Payback Period.
Overall risk reduction.
This comparison supports evidence-based decision-making when selecting risk reduction and climate adaptation measures.