“How we use back-of-the-envelope calculations in our grantmaking” by Open Philanthropy

Emma Buckland, Program Associate in Farm Animal Welfare, drafts a quick back-of-the-envelope calculation for her colleagues.

This post was written by Open Philanthropy Global Health and Wellbeing Staff. Original blog post here.

At Open Philanthropy, our mission is to help others as much as we can with the resources available to us. When making tough calls about which grants will help the most, we rely on a tool that helps clarify expected impact: back-of-the-envelope calculations, or BOTECs.

BOTECs are rough quantitative models that estimate potential grants’ social return on investment (SROI). Open Phil program staff use them to compare a grant's expected benefits to its estimated costs.

Despite the name, most BOTECs wouldn’t actually fit on the back of an envelope. They often involve dozens of assumptions, nested calculations, and scenario planning — especially when we’re modeling larger grants or entire focus areas.

Staff across our Global Health and Wellbeing [...]

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Outline:

(01:46) What BOTECs can (and can't) tell us

(03:15) Sample BOTECs

(03:46) Trialing statins for treating tuberculosis

(10:05) Reducing the cost of pXRF screening

(15:55) Supporting a fundraising organization for effective charities

(17:30) Improving conditions for broiler chickens

The original text contained 21 footnotes which were omitted from this narration.

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First published:
May 28th, 2025

Source:
https://forum.effectivealtruism.org/posts/wxzZQSes2YrXoBDqu/how-we-use-back-of-the-envelope-calculations-in-our

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Narrated by TYPE III AUDIO.

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