While there were some differences between the studies, the core idea was similar enough between the studies to make useful comparisons. (en.hdbuzz.net)
Until then, the most useful comparisons are of national data for single projects and of regional cost and value differences. (realtormag.realtor.org)
The climate forecasts, based on computer models analyzing the past... This is apples and oranges, and is not a very useful comparison. (realclimate.org)