Current charity evaluation models often overlook how organizations within the same cause area influence each other's outcomes. This gap leads to potentially inaccurate impact assessments, as it fails to account for shared funding pools, overlapping beneficiaries, complementary interventions, or competitive dynamics. A tool that models these interdependencies could help funders make better resource allocation decisions.

Understanding Charity Interdependencies

One way to address this would be to create a tool that extends existing evaluation frameworks by allowing users to:

• Define relationships between organizations
• Specify the nature and strength of interdependencies
• Visualize how these relationships affect overall impact
• Compare independent vs. interdependent models through scenario analyses

The tool would be particularly valuable for effective altruism organizations, major foundations, and impact investors who need to understand how funding one charity might affect others in the same space.

Implementation Approach

A minimal version could start with a simple correlation matrix interface for a limited set of charities in one cause area, focusing on basic visualizations of how correlations affect outcomes. This could then expand to:

• More sophisticated relationship types beyond simple correlations
• Multiple cause areas
• Integration with existing charity evaluation platforms

The main challenge would be developing appropriate metrics for different interdependencies while keeping the tool accessible to non-technical users through progressive disclosure of complex features.

Differentiation from Existing Tools

Unlike current charity evaluators that treat organizations independently, this approach would offer:

For platforms like GiveWell, it could show how funding one global health organization affects others. For Open Philanthropy, it could help optimize across their entire grant portfolio rather than just individual grants. The tool would create more nuanced evaluations that better reflect real-world charity ecosystems.

By moving beyond isolated evaluations to model how interventions interact, such a tool could help funders make decisions that account for the complex realities of social impact work.