Today's existing home sales report from the National Association of Realtors was encouraging in sales and prices, but not so much in inventories. The Realtors reported a boost in raw inventory, although the quicker sales pace pushed the month's supply number lower (8 months from 8.5).

But the Realtors don't count the shadow inventory of foreclosed properties, which we know are out there in increasing numbers right now. Also not mentioned was the FHA increasing its upfront premium April 5. Some analysts believe that people were rushing to get in on FHA loans, and that, along with the tax credit may be artificially raising the numbers now.

But then again, what's artificial in today's housing market? All the numbers are so deranged right now. Even the exalted S&P/Case-Shiller Home Price Index folks—who had been pushed to report monthly price numbers with seasonal adjustments, even though year over year is far more accurate—put out a note this week saying that even their monthly seasonal adjustments were no good.

After reviewing the data, the S&P/Case-Shiller Home Price Index Committee believes that for the present time, the unadjusted series is a more reliable indicator of U.S. housing trends than the seasonally adjusted series.

Therefore, the committee suggests that reports "should focus on the year-over-year changes in U.S. home prices where seasonal shifts are not a factor, and if monthly changes are considered, that the unadjusted series should be used.”

The trouble is that government stimulus coupled with an unusual mix of buyers in the marketplace are skewing all comparisons. Home sales are increasing on both the low and the higher end of the market.

I'm just not sure what exactly I'm supposed to compare today's housing market to.

Questions? Comments? RealtyCheck@cnbc.com