EXPLANATION OF REVISIONS

Not adjusted estimates of monthly sales are revised for January 2011 through 

February or March 20141 (if an advance sales estimate is computed), as well as 

end-of-month inventory estimates for January 2005 through February 2014. Not 

adjusted estimates of quarterly retail e-commerce sales are revised for fourth 

quarter 1999 through fourth quarter 2013.

Revised quarterly retail e-commerce sales estimates will be available in the 1st Quarter 

2014 Quarterly E-commerce Sales Report scheduled to be released on May 15, 2014.

Revisions to not adjusted estimates were made in two parts:

First, revisions were made to prior Monthly Retail Trade estimates to reflect 

historical corrections. Then, revisions were made when benchmarking the 

Monthly Retail Trade estimates to the 2012 Annual Retail Trade estimates. 

Revisions to seasonally adjusted estimates were made based on the revised not 

adjusted estimates and revised seasonal adjustment factors

Reasons for Revisions

We revised the not adjusted estimates to: 

• Reflect corrections to data for the current MRTS and ARTS samples. 

Corrections are made to replace previously reported data with more 

accurate data received at a later date or to replace imputed data with 

reported data obtained from the company. 

• Introduce the results from the 2012 ARTS, which has been 

benchmarked using the final results of the 2007 Economic Census.

• Link the previously published estimates from the prior MRTS sample 

to estimate from the current MRTS sample. 

• Reinstate the previously suppressed not adjusted estimates of sales for 

NAICS 44221 (Floor Covering Stores) from 2012 forward. Monthly 

sales estimates for 2012 were revised via benchmarking to the 2012 

ARTS results. Additionally, estimates from 2013 forward were 

analyzed and validated.

We revise the seasonally adjusted estimates to: 

• Reflect revision to the not adjusted estimates. 

• Incorporate changes to the seasonal adjustemen factors based on the 

annual review of the seasonal adjustment models. 

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• Reinstate the previously suppressed seasonally adjusted estimates of 

sales for NAICS 44811 (Men’s Clothing) from January 2001 forward. 

Factors for NAICS 44811 were computed and used to adjust sales for 

August 2006 through February 2014 to reflect a change in the seasonal 

pattern. With this change, the corresponding aggregrates are revised 

back to August 2006. For more information, see the Seasonal 

Adjustment Estimates section.

Benchmarking to 2012 ARTS estimates

There are several reasons for benchmarking estimates from the Monthly Retail 

Trade Survey to the Annual Retail Trade Survey:

• Timing. The respondents have more time to prepare their annual and 

census reports than they do for their monthly reports. The annual and 

census responses are requested at a time when many firms have 

already compiled audited book figures for their own use. The timing of 

the annual survey is such that we are also able to obtain independent 

verification of the reported data from such sources as a company’s 

annual report. On the other hand, respondents to the monthly survey 

have just a few weeks to provide reports of their sales and end-ofmonth inventories. Sometimes these reports are based on incomplete 

or unaudited records and may include estimates made by respondents 

to represent their understanding of their business.

• Sampling. As described in more detail in the Technical 

Documentation, the estimates derived from the annual survey are 

based on a sample that is much larger than the samples used to 

produce the monthly sales or inventory estimates. MRTS estimates are 

benchmarked to the results from the 2012 ARTS, which have been 

indirectly benchmarked using the final results of the 2007 Economic 

Census. See ARTS methodology page for more information

http://www.census.gov/retail/arts/how_surveys_are_collected.html.

• Response. The annual estimates are based on more reported data than 

are the monthly estimates. The response to the ARTS is required by 

law, while the MRTS is voluntary. This requirement results in a total 

quantity response rate (TQRR) of 93 percent for sales and 93 percent 

for inventories and a rate of approximately 72 percent for sales and 69 

percent for inventories for MRTS. An imputation process accounts for 

the sales and inventories data that fail edits or are missing because of 

nonresponse. For MRTS, this process assumes that nonresponding 

firms have similar month-to-month changes to the responding firms of 

a similar size in the same industry. However, the ARTS imputation 

process relies heavily on administrative data and relationships of these 

data for each individual firm, which could result in different data being 

tabulated for the MRTS and ARTS for nonresponding firms.

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Estimates of Monthly Sales

For each detailed NAICS code, the monthly retail and food service sales 

estimates for January 1992 (the beginning of the series) through February 

2013 are linked to the estimates derived from the current sample. The linkage 

is performed at each detailed NAICS level by multiplying the sample-based 

estimates prior to March 2013 by a geometric mean. The geometric mean is 

computed as the square root of the product of two ratios. The numerators of 

the ratios are the Horvitz-Thompson sales estimates for February and March

2013 from the current sample. The denominators of the ratios are the HorvitzThompson estimates for February and March 2013 from the prior sample.

After performing the above linkage, the resulting sales estimates for 

December 2010 through February 2014 are input to the benchmarking 

program. The estimates for a given detailed NAICS code are revised in a 

manner that—

• For 2011 through 2012, constrains the sum of the 12 monthly sales 

estimates to equal the corresponding annual sales estimate from ARTS.

• Minimizes the sum of the squared differences between the month-tomonth changes of the input and revised estimates for December 2010

through February 2014.

• Uses the previously published December 2010 sales estimate as a 

constraint, linking the revised estimates to the previously published sales 

estimates and resulting in no revision to the December 2010 estimate.

A mathematical result of the benchmarking methodology is that, for a given 

NAICS code, all published monthly sales estimates after December 2012 are 

derived by multiplying the Horvitz-Thompson estimates by the ratio of the 

benchmarked-to-input estimate for December 2012. This ratio, which is called 

a carry-forward factor, remains the same and is used to derive published 

monthly sales estimates until the next benchmarking operation.

If a March 2014 advance sales estimate is computed for an industry, the 

estimate may also be revised based on historical corrections made to data for 

February or March 2014. For more information on how advance estimates are 

computed, see the Census Bureau Web site at

http://www.census.gov/retail/marts/how_surveys_are_collected.html.

Revised estimates for aggregate industry levels are computed by summing the 

revised estimates for the appropriate detailed industries comprising the 

aggregate.

Estimates of End-of-Month Inventories

For each detailed NAICS code, the end-of-month inventory estimates for 

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January 1992 (the beginning of the series) through February 2013 are linked 

to the estimates derived from the current sample. The linkage is performed 

using a procedure similar to the one used for sales, except the geometric mean 

is based on end-of-month inventory.

After performing the above linkage, the resulting end-of-month inventory 

estimates for December 2004 through February 2014 are input to the 

benchmarking program. The estimates for a given detailed NAICS code are 

revised in a manner that—

• For 2004 through 2012, constrains the December end-of-month inventory 

estimates from MRTS to equal the end-of-year inventory estimates

derived from ARTS.

• Minimizes the sum of squared differences between the month-to-month 

changes of the input and revised estimates for December 2004 through 

February 2014.

• Uses the previously published December 2004 estimate as a constraint, 

linking the revised estimates to the previously published estimates and 

resulting in no revision to the December 2004 estimate.

For a given detailed NAICS code, end-of-month inventory estimates 

subsequent to December 2012 are derived by multiplying the input estimates 

by the ratio of the benchmarked-to-input estimate for December 2012. This 

ratio is the carry-forward factor for inventory, and it remains the same until 

the next benchmarking operation.

Revised estimates for aggregate industry levels are computed by summing the 

revised estimates for the appropriate detailed industries comprising the 

aggregate.

Estimates of Quarterly E-commerce Sales

For select detail NAICS codes (usually at the 3-digit NAICS level), quarterly 

retail e-commerce sales estimates for fourth quarter 1999 through fourth

quarter 2012 are linked to the estimates derived from the current sample. The 

linkage is performed at these select detail levels by multiplying the samplebased estimates prior to first quarter 2014 by a ratio. The numerators of the 

ratios are the Horvitz-Thompson e-commerce sales estimates for first quarter 

2013 from the current sample. The denominators of the ratios are the HorvitzThompson e-commerce sales estimates for first quarter 2013 from the prior 

sample. Monthly e-commerce estimates are also linked at these select detail 

levels using a procedure similar to the one used for sales, except the geometric 

mean is based on monthly e-commerce sales estimates.

After performing the above linkage, the resulting e-commerce sales estimates 

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for fourth quarter 1999 through fourth quarter 2013 are input to the 

benchmarking program. The estimates for the select detailed NAICS code are 

revised in a manner that—

• For 2000 through 2012, constrains the sum of the 4 quarterly e-commerce 

sales estimates to equal the corresponding annual sales estimate from 

ARTS.

• Minimizes the sum of squared differences between the quarter-to-quarter 

changes of the input and revised estimates for fourth quarter 1999 through 

fourth quarter 2013.

Similarly, the monthly e-commerce sales estimates at these select detail levels for

October 1999 through February 2013 are input into the benchmarking program. 

These estimates for the select detail levels are revised in a manner that—

• For fourth quarter 1999 through fourth quarter 2013, constrains the sum of 

the 3 months in a given quarter to equal the corresponding quarterly ecommerce sales estimate which has been benchmarked to ARTS.

• Minimizes the sum of squared differences between the month-to-month 

changes of the input and revised estimates for October 1999 through 

February 2014.

For select detailed NAICS levels, monthly e-commerce sales estimates 

subsequent to February 2014 will be derived by multiplying the input 

estimates by the ratio of the benchmarked-to-input estimate for fourth quarter 

2012. This ratio is the carry-forward factor for e-commerce sales, and it 

remains the same until the next benchmarking operation.

The revised estimates for the total retail quarterly e-commerce sales are 

computed by summing the revised estimates for the appropriate detailed 

industries comprising the aggregate.

Seasonally Adjusted Estimates

With the exception of NAICS 44811 (Men’s Clothing Stores), new seasonal, trading-day, 

and holiday factors are computed and used to adjust sales for January 2008 through 

February or March 2014 (if an advance sales estimate is computed). Factors for NAICS 

44811 were computed and used to adjust sales for August 2006 through February 2014 to 

reflect a change in the seasonal pattern. Previously suppressed seasonally adjusted 

estimates of sales for NAICS 44811 from January 2001 forward will no longer be 

suppressed. For inventories, new seasonal factors are computed and used to adjust 

inventories for January 2002 through February 2014. For quarterly e-commerce sales, 

new seasonal factors are computed and used to adjust e-commerce sales for fourth quarter 

1999 through fourth quarter 2013. For sales, inventories, and e-commerce sales, the new 

seasonal factors are computed using the revised unadjusted estimates as input to the 

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Census Bureau’s X-13ARIMA-SEATS software and using the X-11 filter-based 

adjustment procedure.

REVISIONS OF SALES AND INVENTORIES

The following table shows a comparison of the revised sales and inventories 

to the previously published estimates for 2013:

2013 Retail and Food Services Sales and Retail Inventories Comparison of the 

Revised Estimates to the Previously Published Estimates

DEFINITION OF TERMS

Dollar Values

All dollar values presented are expressed in current dollars; that is, the 

estimates are not adjusted to a constant dollar series. Consequently, when 

comparing estimates to prior years, users also should consider price level 

changes.

Confidentiality

Title 13 of the United States Code authorizes the Census Bureau to conduct 

censuses and surveys. Section 9 of the same Title requires that any 

information collected from the public under the authority of Title 13 be 

maintained as confidential. Section 214 of Title 13 and Sections 3559 and 

3571 of Title 18 of the United States Code provide for the imposition of 

penalties of up to 5 years in prison and/or up to $250,000 in fines for wrongful 

disclosure of confidential census information. In accordance with Title 13, no 

estimates are published that would disclose the operations of an individual 

firm.

The Census Bureau's Internal Disclosure Review board sets the confidentiality 

rules for all data releases. A checklist approach is used to ensure that all 

potential risks to the confidentiality of the data are considered and addressed.

Disclosure Limitation

A disclosure of data occurs when an individual can use published statistical 

information to identify either an individual or firm that has provided 

information under a pledge of confidentiality. Disclosure limitation is the 

process used to protect the confidentiality of the survey data provided by an 

individual or firm. Using disclosure limitation procedures, the Census Bureau 

modifies or removes the characteristics that put confidential information at 

risk for disclosure. Although it may appear that a table shows information 

about a specific individual or business, the Census Bureau has taken steps to 

disguise or suppress the original data, while making sure the results are still 

useful. The techniques used by the Census Bureau to protect confidentiality in 

tabulations vary, depending on the type of data.

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Unpublished Estimates

It should be noted that some unpublished estimates can be derived directly 

from this report by subtracting published estimates from their respective 

totals. However, the estimates obtained by such subtraction would be subject 

to the poor response rates or high sampling variability.

Individuals who use estimates in this report to create new estimates should 

cite the Census Bureau as the source of only the original estimates.

Adjustment Factors

The X-13ARIMA-SEATS program (version 1.1, build 10) was used to derive 

the factors for adjusting estimates for seasonal variations and, in the case of 

sales, for trading-day and holiday differences. Not adjusted sales and 

inventory estimates for January 1992 through February or March 20141 (if an 

advance sales estimate was computed) were input to this program.

Seasonal adjustment of estimates is an approximation based on current and 

past experiences. Therefore, the adjustment could become less precise because 

of changes in economic conditions and other elements that introduce 

significant changes in seasonal, trading-day, or holiday patterns.

Sales

Sales include merchandise sold (for cash or credit at retail or wholesale) by 

establishments primarily engaged in retail trade. Services that are incidental to 

the sale of merchandise, and excise taxes that are paid by the manufacturer or 

wholesaler and passed along to the retailer are also included. Sales are net, 

after deductions, for refunds and allowances for merchandise returned by 

customers. Sales exclude sales taxes collected directly from customers and 

paid directly to a local, state, or federal tax agency. 

The estimates of sales measure the operations receipts rendered by stores that 

primarily sell at retail. The sales estimates represent total sales and receipts of 

all establishments primarily engaged in retail trade. They do not include sales 

at retail by manufacturers, wholesalers, service establishments, and others 

whose primary activity is other than retail trade. Because the retail 

establishment is the basic unit of measure, the published estimates of sales by 

type of retail store are not intended to measure the total sales for a given 

commodity or merchandise line.

Inventories

Merchandise inventories are the value of stocks of goods held for sale. The 

inventories estimates represent the value, at cost, of the merchandise available 

for sale as of the last day of the report period. Methods of valuation may vary 

according to the accounting practices of each firm. The estimates provided in 

this report are valued on a non-LIFO (last in, first out) basis. Note—LIFO is a 

method of valuing inventory where the latest items of merchandise added to 

the inventory are the first ones taken out. Non-LIFO would mean that another 

method, such as FIFO (first in, first out), was used to establish the value of the 

inventory available for sale. Merchandise inventories are shown for stores and 

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warehouses servicing retail establishments. Included are only those 

warehouses that maintained supplies of merchandise primarily intended for 

distribution within the organization.

Inventories/ Sales Ratios

The inventories/ sales ratios show the relationship of the end-of-month values 

of inventory to the monthly sales. These ratios can be looked at as indications 

of the number of months of inventory that are on hand in relation to the sales 

for a month. For example, a ratio of 2.5 would indicate that the retail stores 

have enough merchandise on hand to cover two and a half months of sales.

E-Commerce

E-commerce is the sale of goods and services where the buyer places an order, 

or the price and terms of the sale are negotiated over an Internet, mobile 

device (M-Commerce), extranet, EDI network, electronic mail or other online 

system. Transactions are agreements between buyers and sellers to transfer 

ownership of, or rights to use, goods or services. Payment for these goods and 

services may or may not be made online.

Leased Department

Leased departments are broadly defined as operations of one company 

conducted within the establishment of another company. Typical examples 

may include jewelry counters or optical centers within department stores.

GAFO

GAFO represents sales at stores that sell merchandise normally sold in 

department stores. GAFO includes the following kinds of retail businesses:

• General merchandise stores (NAICS 452).

• Clothing and clothing accessories stores (NAICS 448).

• Furniture and home furnishings stores (NAICS 442).

• Electronics and appliance stores (NAICS 443).

• Sporting goods, hobby, book, and music stores (NAICS 451).

• Office supplies, stationery, and gift stores (NAICS 4532).

ADDITIONAL INFORMATION

Survey Questionnaires

The ARTS questionnaires can be found on the Census Bureau Web site at 

http://www.census.gov/retail/arts/get_forms.html. The MRTS questionnaires 

can be found on the Census Bureau's Web site at 

http://www.census.gov/retail/mrts/get_forms.html.

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1 Advance sales estimates are computed for selected kinds of business and are based on a small subsample 

selected from the larger MRTS sample.

Related Links:

Advance Monthly Retail Trade & Food Services

Monthly Retail Trade Survey

Annual Retail Trade Survey

E-Stats – Measuring the Electronic Economy

Source: Retail Indicators Branch, U.S. Census Bureau

Last Revised: April, 30 2014

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