Valuing free goods

There is a new AEJ Macro paper by Brynjolfsson, et.al. on how to value free goods.  Here is one of the concrete measures:

Using this approach, we estimate the reservation price [for giving up Facebook] to be $2,152 in 2003 US dollars.

That is for the 2017 version of Facebook.  Note this does not measure “whether Facebook is really good for you on net,” but it does indicate some fairly strong demand.  And:

…the estimate contribution to welfare due to Facebook in the US over the period 2003-2017 is $231 billion (in 2017 dollars), which translates to $16 billion on average per year.