Some thoughts were collected from careful observers of philanthropy — people who either make decisions about how to use charitable wealth or advise those who do — on the value of time-limited giving. Specifically, we asked: Under what conditions could one argue, objectively and convincingly, that giving a large amount over a limited period produces more value for society than giving smaller amounts over a much longer, perhaps indefinite, timespan.

Some formulas were suggested that could illustrate (but not literally govern, in any strict, mathematical sense) how a foundation might weigh that kind of choice. We focused on:

  • the dollars the foundation plans to inject into a field or a community;
  • the benefits those dollars are expected to produce directly;
  • the risk that those benefits would not, in fact, be produced;
  • the possible erosion of the benefits over time;
  • improvements in the foundation’s effectiveness or efficiency in making beneficial investments; and
  • the ripples that the direct benefits might later cause, essentially as after-effects.

Read the source article at Philanthropy Central