Where do we put our energy?

I listened to a TED video today.  It is focused on the basic question ?Given $50 billion to spend, which would you solve first, AIDS or global warming? Danish political scientist Bjorn Lomborg comes up with surprising answers.  

http://www.ted.com/index.php/talks/bjorn_lomborg_sets_global_priorities.html

Taking this to our role in teaching and learning.  There are many problems.  Rather than prioritize problems, we should look at prioritizing solutions.  Bjorn worked with economists to determine the cost/benefit of solutions.  In terms of technology, what technologies would have the best cost / benefit ratio.  If we can help more students by doing X than helping less students with Y, which choice should we make.

I don't have the answers to the cost / benefit of providing 1 to 1 laptop initiatives.  Rather than that specific problem I think we should ask ourselves if we are making the best choices with not only technology, but how we spend our time teaching and learning.

Is there a way to show that the cost / benefit of providing school and home computers with internet access to all students is more beneficial than providing targeted support to only students that need it (after they are already falling behind in their learning and then identified to receive support.)

My statement is not which one is better, rather that decisions around the world seem to be made all in the name of 'putting learners first.'  

Do we really know what uses of technology if any are more beneficial?