Not only should you not trust their forecasts, don’t trust their data. According to Florida broker Mike Morgan (through Mish), there’s a strong belief they cherry pick data.
Here’s the money quote:
NAR extrapolates. They survey 1-2% of the market and then multiply and add a “fudge” factor. He said he believes they intentionally avoid distressed markets like Miami, Naples, Vegas, Phoenix, DC, etc. There (sic) goal, as our Trade Association, is to promote the industry, not to report a comprehensive picture. If they avoid the hard hit markets, their numbers will consistently paint a much better picture than what reality is.