Research Data FAQ

Housing Indicators

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Existing Home Sales

Q: Where do I find month's supply, inventory data, and sales price data for existing home sales?
A: Months' supply data is listed on the Existing Home Sales Overview which covers the past three years of annual data and the past year of monthly data. You can access the PDF files on the EHS page here.  Months' supply data is found in the last column on the right. Inventory is found in the column second from the right. Price data is found at the bottom half of the document.

Q: Does Existing Home Sales data track foreclosures?
A: Our existing home sales data includes some foreclosures but not all. A property must be listed with a Multiple Listing Service (MLS) by Realtors® to be included in our inventory, and sold through an MLS to be included in our sales figures. When a foreclosure sale is not successful, the numbers of sales do not increase and it will get counted in our inventory figure.

Q: If I am part of an MLS or a Local Board, how do I submit monthly data to be included in the EHS data series?
A: Instructions and specifications for submitting existing home sales data can be found here.

Housing Affordability

Q: How do I interpret the index?
A: A value of 100 means that a family with the median income has exactly enough income to qualify for a mortgage on a median-priced home. An index above 100 signifies that family earning the median income has more than enough income to qualify for a mortgage loan on a median-priced home, assuming a 20 percent down payment.

Q: How are a typical family and home defined by NAR?
A: A typical home is defined as the national median-priced, existing single-family home as calculated by NAR. The typical family is defined as one earning the median family income as reported by the U.S. Bureau of the Census.

Local Housing Affordability Index

Q: Does NAR produce a local affordability index?
A: No. We do have some information on the affordability index in our Local Market Reports (you will need your Member ID to access it). You can also visit our page on the methodology for the Housing Affordability Index.

New Home Sales and Inventory

Q: Does NAR keep information on new home sales or inventory?
A: No. Information on new home sales and inventory is collected by the Census Bureau and can be found here.

Pending Home Sales Index

Q: What data are included in the Existing and Pending Home Sales?
A: NAR uses data obtained from Multiple Listing Services (MLSes) to generate the EHS and PHS statistics. Properties that are listed with a Realtors® are included. Properties that are not listed with a Realtors® such as For-Sale-By-Owner (FSBO) or auction properties are not included in our statistics.

Q: Does NAR have any data indicating the percentage of pending home sales that are foreclosed properties or similar data for existing home sales?
A: Lawrence Yun gives the most current information on foreclosures in the data in the existing or pending home sales press releases at the beginning of each month. This can be accessed here.

Median: What Does it Mean?

In a world of statistical averages, many have asked why the Economic Research Group of the NATIONAL ASSOCIATION OF REALTORS® reports a median home sale value instead of a mean in its monthly Existing-Home Sales reports (as well as most of its other industry statistics). There are many people who believe the mean is easier to understand than the median. But the median measure is not difficult to appreciate. Let's start with defining and differentiating between the two measures.

A mean is calculated by adding up all the values in a distribution and then dividing the sum by the total number of values contained in that distribution. To find a median value, one takes all of the values in the distribution, sorts in ascending order, lines them up and finds the middle value.

They sound similar, and in may instances, there is not much difference between the two values. But the reason NAR concentrates on the median instead of the mean is because the mean value calculation has a limitation that can prevent it from reflecting an "average." In calculating home sales price statistics this limitation occurs when the sale price of one home varies greatly from the remainder of the homes. This can skew the average.

For instance, suppose we encounter a small town calculating its home sales statistics for March of 2000. In March, six homes in Smalltown, USA were sold at the following prices:

  • $80,000
  • $110,000
  • $90,000
  • $120,000
  • $100,000
  • $130,000

In this situation, the mean would be $105,000, the median would be $105,000, and everything works out great.

But suppose instead of six homes, seven were sold and the seventh home sold for $250,000. Now the median would be $110,000, but the mean would dramatically increase to $125,700. Yet, only two homes sold for more than the mean, while five sold for less.

This type of situation can be seen in the U.S. home sale price distribution for March 2000. The median price, however, indicates half of the homes sold for more and half sold for less. The mean has been pulled from the apex of the distribution by the 5% of the homes that sold for more than $500,000.

It is important to notice the distribution of home sales is not a normal bell-shaped distribution. Rather, there are a high number of sales in the lower end of the price scale, which produces a long tail sloping down toward the lower end of the scale. This type of distribution shows it would not be appropriate to emphasize the mean price of $175,300 when the majority of the homes sold in the $100,000-$160,000 range. The median price of $136,900 better reflects the selling price of homes in a given time period.

While the mean price may be useful in discussions on aggregate home sales and dollar volume of home sales, the "average" homebuyer/seller learns more about the price of a typical home from the median price. If buyers and sellers respond to the mean price of $175,300, "average" sellers may have set the asking price too high. Buyers could be misled into believing they cannot afford to purchase a home. This would discourage people from entering the market and be counterproductive for the real estate industry.

Regional Definitions

The regional definitions used in NAR’s existing home sales, pending home sales and housing affordability data series are identical to those used in the US Census. They divide the nation into four regions, as seen below:


New Hampshire
New Jersey
New York
Rhode Island


North Dakota
South Dakota


District of Columbia
North Carolina
South Carolina
West Virginia


New Mexico



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Commercial Real Estate

Q: Does NAR have any data on commercial real estate?
A: Yes. All links to commercial data can be found here.

Foreclosures and Short Sales

Q: Does NAR have data on foreclosures and short sales?
A: Information on both foreclosures and short sales can be found in the REALTORS® Confidence Index, a key indicator of housing market strength based on a monthly survey of over 50,000 real estate practitioners. You can read the survey here.

International Real Estate

Q: Does NAR have any international information?
A: Yes. All links to international data can be found here.

Labor Statistics

Q: Does NAR have labor statistics?
A: Labor information is covered by the Bureau of Labor Statistics. You can access this information here.

Local Market Reports

Q: Where can I find information on my local market?
A: Research has local information on markets, state taxes and fiscal conditions, wealth gain by metro area, subprime ARM performance, mortgage conditions, the economic impact of real estate, and existing home sales and prices. All of these local reports can be found here.

Q: Does NAR have a directory of all state and local association websites?
A: Yes. You will need your Member ID and password to log in and view this information, as this is provided for members only. You can access this information  here.

MLS Economic & Market Watch Report

Q: How do I interpret the local market reports?
A: NAR has compiled a PDF on how to read the local market reports which require a member log in, and can be accessed here.

Q: What factors are taken into account in each report?
A: The health of the local job market, foreclosure rates, housing inventory, debt-to-income and mortgage-servicing-costs-to-income ratios are all taken into account when compiling each report. You can find the reports here.

Month's Supply

Q: What methodology is used to calculate months' supply?
A: The month's supply for March is the inventory at the end of the month of March divided by seasonally adjusted annualized closed sales in March divided by 12.
E.g., using hypothetical figures:

  • 4.2 million homes for sale
  • 4.9 million seasonally adjusted closed sales
  • Adjust back to month's pace by dividing by 12
  • Month's supply = 4.2million/(4.9 million sales/12) = 10.3 months supply

Q: Is it based on pending or closed sales?
A: Month's supply is based on closed sales.

State & Local Market Info

Q: Where do I find data on home prices for (state/county/MLS)?
A: We have median home price data, but historical data is not publicly available. You can purchase historical data by contacting NAR's Research department at You can also access online state and local information.

State Economic Impact on Housing

Q: What factors are taken into account when deriving a state's impact on housing?
A: NAR looks at home construction, real estate brokerage, mortgage lending, title insurance, home appraisal, and renting and leasing when compiling each state report. You can find a link to the report here.


General Questions

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Median Prices

Q: What is the difference between Case-Shiller, OFHEO, and NAR median prices?
A: Research has an entire webpage dedicated to answering this popular question, and can be found here. 


Q: What is the methodology for the Profile of Home Buyers & Sellers?
A: In August 2008, The NAR mailed an eight -page questionnaire to 133,000 consumers who purchased a home between July 2007 and June 2008. The survey yielded a 10,053 usable responses with a response rate, after adjusting for undeliverable addresses, of 7.9 percent. Consumer names and addresses were obtained from Experian, a firm that maintains an extensive database of recent home buyers derived from county records. Information about sellers comes from those buyers who also sold a home.

All information in this Profile is characteristic of the 12-month period ending June 2008, with the exception of income data, which are reported for 2007. In some sections comparisons are also given for results obtained in previous surveys. Not all results are directly comparable due to changes in questionnaire design and sample size. Some results are presented for the four U.S. Census regions: Northeast, Midwest, South and West. The median is the primary statistical measure throughout this report. Due to rounding and omissions for space, percentage distributions may not add to 100 percent.

Q: What is the methodology for the Member Profile?
A: In February 2008, NAR mailed an 89-question survey to a random sample of 72,000 Realtors®. An identical questionnaire was also distributed to another group of 89,400 members via a Web-based online survey. A total of 9,997 responses were received. After accounting for undeliverable questionnaires, the survey had an adjusted response rate of 7.7 percent. Survey responses were weighted to be representative of state level NAR membership. Information about compensation, earnings, sales volume and number of transactions are characteristics of calendar year 2007, while all other data are representative of member characteristics in early 2008.

NAR is committed to equal opportunity in the real estate industry. In accordance with this commitment, racial and ethnic information was collected and is included in this report. Where relevant, we present information on Realtors® in subgroups based on the license held by members of NAR: a broker, broker-associate, sales agent or appraiser license. The term "broker" refers to Realtors® holding a broker or broker associate license unless otherwise noted. In some cases, information is presented by Realtors®' main function within their firm or their real estate specialty regardless of the type of license held.

The primary measure of central tendency used throughout this report is the median, the middle point in the distribution of responses to a particular question or, equivalently, the point at which half of the responses are above and below a particular value. Data may not be comparable to previous Member Profile publications due to changes in questionnaire design.

Real Estate Brokers

Q: What is the total number of licensed real estate brokers?
A: Realtors® are licensed real estate brokers who are members of the National Association of Realtors®. Approximately half of the nation's licensed brokers are members of NAR. NAR's current membership can be found here:
Annual data
Monthly report
For more information you can also visit the Association of Real Estate License Law Officials.

Q: Do you track broker-specific information, such as sales volume or number of sides by broker?
A: No, we do not track that, but an organization called RealTrends does. You can find that information here.

Research Resources

Q: Where can I find a list of data, survey, presentations, products, and other resources that Research creates?
A: That list is called the Research Resource Guide, and can be found here.

Seasonal Adjustment

Q: What is seasonal adjustment?
A: A seasonal adjustment is an adjustment made to data to account for seasonal patterns such as the fact that due to family moves over the summer months between school years, more homes are sold in that time of the year than any others.

Q: Is NAR data seasonally adjusted?
A: NAR seasonally adjusts the existing home sales data so that we can compare the sales in February with the sales in August and not worry that the difference is a result of seasonal pattern. NAR does not adjust the median home price series, so those data should not be compared month-to-month. Instead, we compare the change in home prices from one year prior. For more detail, see our economist commentary on this issue here.