While Holden didn't say that it doesn't matter where you donate and that charity markets are perfectly efficient, he did say that it's more efficient than we think and that much of the low-hanging fruit is taken (among mainstream causes): "While I do believe we’ve found some places in which more money is needed to deliver more proven cost-effective interventions, doing so has been far more difficult than I expected... it seems nearly impossible to find a promising area or idea that is completely ignored (though many may be underfunded relative to other areas and ideas)."
While Holden didn't say that it doesn't matter where you donate and that charity markets are perfectly efficient, he did say that it's more efficient than we think and that much of the low-hanging fruit is taken (among mainstream causes): "While I do believe we’ve found some places in which more money is needed to deliver more proven cost-effective interventions, doing so has been far more difficult than I expected... it seems nearly impossible to find a promising area or idea that is completely ignored (though many may be underfunded relative to other areas and ideas)."