by Calculated Risk on 7/29/2014 11:52:00 AM

I've been expecting a slowdown in year-over-year prices as "For Sale" inventory increases, and the slowdown is here!   The Case-Shiller Composite 20 index was up 9.3% year-over-year in May; the smallest year-over-year increase since January 2013.

This is still a very strong year-over-year change, but on a seasonally adjusted monthly basis, the Case-Shiller Composite 20 index was down 0.3% in May.  This was the first monthly decrease since prices bottomed in early 2012.  (Note: The seasonal factor is skewed by foreclosures).

On a real basis (inflation adjusted), prices actually declined for the second consecutive month.  The price-rent ratio also declined in May for the Case-Shiller Composite 20 index.

It is important to look at prices in real terms (inflation adjusted).  Case-Shiller, CoreLogic and others report nominal house prices.  As an example, if a house price was $200,000 in January 2000, the price would be close to $280,000 today adjusted for inflation (40%).  That is why the second graph below is important - this shows "real" prices (adjusted for inflation).

Nominal House Prices

The first graph shows the quarterly Case-Shiller National Index SA (through Q1 2014), and the monthly Case-Shiller Composite 20 SA and CoreLogic House Price Indexes (through May) in nominal terms as reported.

In nominal terms, the Case-Shiller National index (SA) is back to mid-2004 levels (and also back up to Q2 2008), and the Case-Shiller Composite 20 Index (SA) is back to October 2004 levels, and the CoreLogic index (NSA) is back to January 2005.

Real House Prices

The second graph shows the same three indexes in real terms (adjusted for inflation using CPI less Shelter). Note: some people use other inflation measures to adjust for real prices.

In real terms, the National index is back to Q4 2001 levels, the Composite 20 index is back to July 2002, and the CoreLogic index back to January 2003.

In real terms, house prices are back to early '00s levels.

Price-to-Rent

In October 2004, Fed economist John Krainer and researcher Chishen Wei wrote a Fed letter on price to rent ratios: House Prices and Fundamental Value. Kainer and Wei presented a price-to-rent ratio using the OFHEO house price index and the Owners' Equivalent Rent (OER) from the BLS.

Here is a similar graph using the Case-Shiller National, Composite 20 and CoreLogic House Price Indexes.

This graph shows the price to rent ratio (January 1998 = 1.0).

On a price-to-rent basis, the Case-Shiller National index is back to Q1 2002 levels, the Composite 20 index is back to November 2002 levels, and the CoreLogic index is back to May 2003.

In real terms, and as a price-to-rent ratio, prices are mostly back to early 2000 levels.  And real prices (and the price-to-rent ratio) have declined for two consecutive months using Case-Shiller Comp 20.