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Explanation of the United States Census Bureau’s Supplemental Quarterly ECommerce Data Product1

1 Introduction

A dynamic retail economy garners great attention every day as it evolves to meet consumers’ 

changing needs and to adapt to emerging technologies. The evolution of e-commerce is a 

particularly noteworthy topic to retail industry experts, analysts, policymakers, and consumers. 

As a result, there is increased interest in the Census Bureau’s retail data products that measure

the e-commerce component of the retail economy. In order to meet the needs of its data users, 

the United States Census Bureau has made it a priority to: 

1. Evaluate the current definition of e-commerce.

2. Produce additional e-commerce data products where quality standards and resources

allow.

The first priority is a long-term goal. A group of Census Bureau retail and classification subject 

matter experts are working with retail industry experts to better understand how different retail 

industry stakeholders—be it retailers, real estate developers, financial institutions, or retail trade 

groups, among others—define and track e-commerce. 

The second priority is a short-term goal. A Census Bureau E-Commerce Data Analysis Team 

was tasked with researching the feasibility of using already collected data to produce one or 

more supplemental e-commerce tables. These tables would be published in conjunction with the 

Quarterly E-Commerce Report. The Census Bureau currently produces the following ecommerce data products on a monthly or quarterly basis:

• On a monthly basis, the Monthly Retail Trade Report includes estimates for companies

classified by the North American Industry Classification System (NAICS) as Nonstore

Retailers (NAICS 454) and a subset of those companies in NAICS 4541 called Electronic

Shopping and Mail-Order Houses. However, other retailers that may not be conducting ecommerce, including electronic auctions and mail-order houses, are also included in these

estimates.

• On a quarterly basis, the Quarterly E-Commerce Report is published. This report

provides a single quarterly estimate measuring all retail e-commerce sales captured by the

Monthly Retail Trade Survey (MRTS).

The purpose of this document is to share the findings of the work done on the second priority. 

Using existing MRTS data, a quarterly supplemental e-commerce table has been developed to

provide more granular e-commerce sales estimates.

1 The Census Bureau has reviewed this data ensure appropriate access, use, and disclosure avoidance protection of the

confidential source data (Project No. P-7504206, Disclosure Review Board (DRB) approval number: CBDR-FY24-003).
2

2 Overview of Census Retail Programs 

The retail trade program currently covers retail companies as defined by NAICS and represents 

all retail companies (NAICS Sector 44-45) with and without paid employees. These retail 

businesses may be large retailers with many store locations, single-unit retailers with only one 

location, or retailers operating solely as e-commerce businesses. 

The Census Bureau measures the retail economy every five years in the Economic Census and 

on a more frequent basis in monthly and annual surveys. In years ending in “2” and “7”, the 

Economic Census asks for detailed sales and product-level information as well as employment 

and payroll and business characteristics for each physical store location that a retailer operates. 

Response to the Economic Census is mandatory and the data collected are used to update the 

Census Bureau’s Business Register from which the sampling frames for many Economic 

Directorate surveys—including the annual and monthly retail trade surveys—are created. Each 

year, the Annual Retail Trade Survey (ARTS) collects data at the company or retailer level 

nationally; no store location data are collected. The ARTS collects annual sales, e-commerce 

sales, end-of-year inventories, and expenses data as well as some retailer characteristics; the 

annual data are released approximately 15 months after the data year ends. 

The MRTS is a voluntary survey conducted at the retailer or company level and collects 

sales/receipts as well as end-of-month inventories and e-commerce sales from all retail 

industries. Estimates from this survey are released approximately six weeks after month’s end. 

The MRTS is a subsample of the ARTS and a selection of the MRTS sample occurs 

approximately every five years to ensure the sample remains representative and to redistribute 

the burden for small and mid-size businesses. A stratified simple random sampling method is 

used to select approximately 10,800 retail firms whose sales are then weighted and benchmarked 

to represent the complete universe of retail firms. The MRTS sample is probability based and 

represents all employer firms engaged in retail activities as defined by NAICS. Coverage 

includes all retailers whether or not they are engaged in e-commerce. Online travel services, 

financial brokers and dealers, and ticket sales agencies are not classified as retail and are not 

included in either the total retail or retail e-commerce sales estimates. Nonemployers are 

represented in the estimates through benchmarking to prior annual survey estimates that include 

nonemployer sales based on administrative records and imputation and e-commerce sales 

through imputation. E-commerce sales are included in the total monthly sales estimates. 

The MRTS sample is updated on an ongoing basis to account for new retail employer businesses 

(including those selling via the Internet), business deaths, and other changes to the retail business 

universe. Firms are asked each month to report e-commerce sales separately. For each month of 

the quarter, data for nonresponding companies are imputed from responding companies falling 

within the same kind of business and sales size category. Responding firms account for 

approximately 71 percent of the e-commerce sales estimate and about 71 percent of the estimate 

of U.S. retail sales for any quarter. 

Retailers are sampled by primary kind-of-business as classified by NAICS code. However, if a 

retailer engages in more than one kind-of-business (e.g, food and beverage stores, general 
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merchandise stores, etc), it can have more than one tabulation part. This means that a company 

contributes to estimates of each of the different kinds-of-business it conducts. Note that in 

general, companies with a tabulation part in NAICS 4541 may have multiple kinds of brick-andmortar businesses, but all e-commerce sales are reported under one NAICS 4541 part.

Retail e-commerce sales are estimated from the same sample used for the MRTS to estimate 

preliminary and final U.S. retail sales. 

3 Project Objective

The core objective of the E-Commerce Data Analysis Team is to analyze existing e-commerce 

data and determine if the data and data quality would allow for publishing more granular ecommerce sales.2

This effort mimics the effort that led to the publication of an annual supplemental e-commerce 

table released as part of the 2015 Annual Retail Trade Survey (ARTS). ARTS has long published 

a table that contains total sales and total e-commerce sales for each 3-digit NAICS code. 

Figure 1 shows an example of this annual data presentation for 2016 and 2017.

NAICS 

Code

2017 2016r

Kind of Business Total E-commerce Total E-commerce

Total Retail Trade 5,046,894 461,034 4,851,774 397,307

441 Motor vehicle and parts dealers 1,174,417 34,273 1,142,261 31,913

442 Furniture and home furnishings stores 113,783 1,335 110,695 1,122

443 Electronics and appliance stores 99,401 2,078 99,297 1,954

444 Building mat. and garden equip. and supplies 

dealers 365,651 2,583 349,372 2,260

445 Food and beverage stores 725,915 3,802 699,362 2,435

446 Health and personal care stores 333,219 S 327,031 D

447 Gasoline stations 452,856 S 418,684 D

448 Clothing and clothing access. stores 258,472 9,898 259,840 8,854

451 Sporting goods, hobby, musical instrument, 

and book stores 84,264 2,423 86,562 2,288

452 General merchandise stores 683,854 453 675,374 362

453 Miscellaneous store retailers 125,500 4,053 121,740 3,766

454 Nonstore retailers 629,562 399,178 561,556 341,430

4541 Electronic shopping and mail-order houses 552,214 397,490 488,619 339,928

D - Denotes an estimate withheld to avoid disclosing data of individual companies; data are 

included in higher-level totals; S – Suppressed

Figure 1: Estimated Annual U.S. Retail Trade Sales - Total and E-commerce: 2016-2017

Estimates are shown in millions of dollars and are based on data from the Annual Retail Trade 

Survey.

Source: https://www2.census.gov/programs-surveys/arts/tables/2017/ecommerce.xls

In recent years, data users have requested more detailed e-commerce sales information. In 2017, 

ARTS introduced a new supplemental e-commerce table that is now included as part of its 

annual publication. This data product uses existing data collected from nonstore retailers in 

2

Information on the history of the existing E-Commerce definition and measurements can be found in Thomas L. Mesenbourg’s 

Measuring the Digital Economy working paper. Working paper available here: 

https://www.census.gov/content/dam/Census/library/working-papers/2001/econ/umdigital.pdf
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NAICS 4541 and further breaks out that data by primary kind-of-business for those nonstore 

retailers.

If a company operates in more than one industry, it is asked to report for each industry 

separately. This allows the company’s data to be tabulated in the correct industries.3 When a 

company has a large e-commerce segment—typically with separate warehousing facilities—

ARTS considers this a separate industry from the company’s brick-and-mortar NAICS 

classifications. Appendix A provides examples of how these types of company structures are 

created and tabulated in retail and e-commerce sales estimates.

For companies with separate store and e-commerce components as described above, the 

supplemental e-commerce table reallocates the sales of the NAICS 4541 component to the 

primary business activity (3-digit NAICS code) of the company. 'Primary business activity' refers 

to the 3-digit NAICS code having the most sales for the company when the sample was selected. 

For example, consider two separate companies (Company A and Company B) that both have a 

brick-and-mortar component (NAICS code 448110, which is Men's Clothing Stores) and an ecommerce component (NAICS code 454111, which is Electronic Shopping). When the sample 

was selected, the majority of Company A's sales were under NAICS code 448110. Consequently, 

the primary business activity of Company A is 448, and the sales of the NAICS 4541 component 

of Company A are under 448 in the supplemental table. Conversely, when the sample was 

selected, the majority of Company B's sales were under NAICS code 454111. Thus, for 

Company B, the primary business activity is 454, and the sales of the NAICS 4541 component of 

Company B are under 454 in the supplemental table. Companies without a brick-and-mortar 

component remain classified under NAICS 454. Figure 2 shows an example of this annual data 

presentation for 2016 and 2017.

3 Note that this only refers to operating different types of stores, not to selling multiple types of products within a single type of 

store.
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NAICS Code of 

Primary Business 

Activity3

2017 2016r

Kind of Business Total E-commerce Total E-commerce

Total Electronic Shopping and Mail-Order Houses 552,214 397,490 488,619 339,928

441 Motor vehicle and parts dealers 530 528 496 496

442 Furniture and home furnishings stores 8,214 7,756 7,275 6,878

443 Electronics and appliance stores 30,791 30,762 25,639 25,627

444 Building material and garden equipment and supplies 

dealers D 10,363 D 7,542

445 Food and beverage stores 1,531 1,400 1,476 1,358

446 Health and personal care stores D 3,722 D 3,296

447 Gasoline stations ZZ ZZ ZZ ZZ

448 Clothing and clothing accessories stores 25,206 24,778 23,635 23,176

451 Sporting goods, hobby, musical instrument, and book 

stores 5,949 5,548 5,959 5,634

452 General merchandise stores D 31,744 27,477 27,167

453 Miscellaneous store retailers D 11,518 D 10,154

454 Nonstore retailers 371,757 269,371 329,381 228,600

D - Denotes an estimate withheld to avoid disclosing data of individual companies; data are 

included in higher-level totals. ZZ - Estimate is less than $500,000. 

Figure 2: Supplemental Estimated Annual Sales for U.S. Electronic Shopping and Mail-Order 

Houses (NAICS 4541) - Total and E-commerce Sales by Primary Business Activity: 2016-2017

Estimates are shown in millions of dollars and are based on data from the Annual Retail Trade 

Survey. 

Source: https://www2.census.gov/programs-surveys/arts/tables/2017/supecommerce4541.xls

4 Supplemental Quarterly E-Commerce Table

After the annual supplemental table was published, data users expressed the usefulness of this 

new table but requested that the estimates in the table be published on a more frequent basis: 

either monthly or quarterly. The E-Commerce Data Analysis Team initially replicated the tables 

displayed in Figures 1 and 2 at a quarterly frequency using existing monthly retail sales data 

collected by the Monthly Retail Trade Survey.4 The Team used the same methodology in 

creating these tabulations that was employed by ARTS. When these tables were created, 

numerous sales estimates required suppression due to disclosure protections and data quality 

concerns. For many survey data products, including the retail surveys, the current quality 

practice is to suppress as follows:

• If 50% or more of the estimate is imputed, the data should not be published.

• If the coefficient of variation equals or surpasses 30%, the data should not be published.

• If the estimate does not pass disclosure review, the data cannot be published and is

further protected so a reader cannot calculate the suppressed value.

o Data collected in the MRTS are subject to legal confidentiality protections (U.S.

Code Title 13, Section 9 [1,5]).

4 The scope of the e-commerce work currently only covers Retail Trade. Food Services (NAICS 722) are excluded 

from the work.
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o MRTS uses cell suppression for disclosure avoidance. Cell suppression is a 

disclosure avoidance technique that protects the confidentiality of individual 

survey units by withholding cell values from release and replacing the cell values 

with a symbol, usually a “D”. If the suppressed cell value were known, it would 

allow one to estimate an individual survey unit’s value too closely. The cells that 

must be protected are called primary suppressions. To make sure the cell values 

of the primary suppressions cannot be closely estimated by using other published 

cell values, additional cells may also be suppressed. These additional suppressed 

cells are called complementary suppressions. The process of suppression does not 

change the higher-level totals.

Balancing the requests and needs of data users with the value of publishing a table with limited 

information, the Team sought feedback from internal and external stakeholders. One idea 

proposed during the feedback gathering was to combine the data in Figure 1 and Figure 2 to 

create a whole picture of e-commerce sales by primary kind-of-business. For example, rather 

than looking at clothing store e-commerce sales for clothing store retailers (NAICS 448 in Figure 

1) and clothing nonstore retailers (the 448 breakout of 4541 in Figure 2) individually, this table 

would combine the e-commerce sales for the two and create total clothing store and nonstore 

sales and e-commerce sales estimates. 

To produce the MRTS sales estimates, the following methodology is used. For each month of the 

quarter, Horvitz-Thompson estimates are obtained by summing weighted e-commerce sales 

(either reported or imputed). Benchmarked monthly estimates are computed by multiplying each 

Horvitz-Thompson estimate by the carry-forward factor calculated during the most recent 

benchmarking. Estimates for the quarter are obtained by summing the monthly benchmarked 

estimates. For companies with separate store and e-commerce components, the e-commerce 

components are tabbed in MRTS under NAICS 4541.

To calculate the sales and e-commerce estimates in the supplemental quarterly e-commerce 

table, first subtotal Horvitz-Thompson estimates are obtained by summing weighted sales and ecommerce sales within 4541 by the primary kind-of-business of the company. Note these 

companies are only tabbed under their primary kind-of-business even though they may operate in 

multiple kinds-of-business. To ensure the overall total retail estimates are consistent with MRTS, 

these kind-of-business subtotals are raked to the benchmarked monthly estimate for NAICS 4541 

from MRTS. This is done by calculating the proportion of each kind of business to the HorvitzThompson estimate of NAICS 4541, then applying each of these proportions to the benchmarked 

monthly estimate for NAICS 4541 to get the corresponding benchmarked monthly estimate for 

that kind of business subtotal. Finally, these kind-of-business nonstore subtotals are added to the 

MRTS estimate for that kind of business to get a total store and nonstore estimate.5 Note that the 

Nonstore line of the table contains the remaining NAICS 454 companies, including NAICS 4541 

companies whose primary kind-of-business is nonstore, after the other companies’ NAICS 4541 

parts are removed.

5 For more information on the current quarterly E-commerce methodology as well as the supplemental table, please visit 

https://www.census.gov/retail/ecommerce/how_surveys_are_collected.html
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These combined estimates also presented a number of disclosure and data quality issues. To 

overcome these issues while still publishing as many e-commerce sales estimates as possible, the 

Team created groups of kinds-of-businesses. Total store and nonstore sales estimates are 

provided in the table at the grouping levels but not at the separate kinds-of-business. However, 

total e-commerce sales estimates are provided at the grouping level and at the separate kinds-ofbusiness level. For example, total sales for retailers whose kinds-of-business are in furniture and 

home furnishings; electronics and appliance; and building materials, garden equipment and 

supplies are combined to produce a furniture, building materials, and electronics total store and 

nonstore estimate. This grouping approach was necessary to produce a table with sufficient

disclosure protections.

Based on this methodology, a new supplemental quarterly e-commerce table was originally

released as an experimental data product on August 28th, 2019. As of the 4th Quarter 2021 

release on February 18, 2022, this is now a standard data product. Data in this table are available 

back to 2018Q2 when the current MRTS sample was introduced. Figure 3 shows an example of 

this table.

Kind of Business

Retail Sales (millions of dollars)

2019Q2 2019Q1 2018Q4

(p) (p) (p)

Total Store 

and Total Total Store and Total Total Store and Total

Nonstore 

Sales

ECommerceNonstore 

Sales

ECommerceNonstore 

Sales

ECommerce

Total Retail Trade 1,377,719 139,671 1,241,540 129,015 1,407,934 160,894

Motor vehicle and parts 322,912 9,609 289,748 8,697 297,397 9,169

Furniture, building materials, and 

electronics 173,939 S 146,516 S 171,411 18,970

Furniture and home furnishings * 2,505 * 2,344 * 2,934

Electronics and appliance * S * S * S

Building materials, garden 

equipment and supplies * 3,995 * 3,018 * 3,449

Clothing and general merchandise 257,621 17,679 230,698 16,275 306,894 27,368

Clothing and clothing accessories * 9,028 * 8,833 * 13,710

General merchandise * 8,651 * 7,442 * 13,658

All other 489,958 9,131 445,976 8,962 487,336 10,735

Food and beverage * 1,843 * 1,840 * 1,935

Health and personal care * 1,219 * 1,065 * 1,609

Sporting goods, hobby, musical 

instrument, and books * 1,347 * 1,399 * 2,072

Miscellaneous including gasoline 

stations * 4,722 * 4,658 * 5,119

Nonstore retailers 133,289 85,716 128,602 79,337 144,896 94,652

S – Suppressed; * - not published

Figure 3: Supplemental Estimated Quarterly U.S. Retail Trade Sales - Total and E-commerce1: 

2019Q2. Estimates are not adjusted and based on data from the Monthly Retail Trade Survey and 

administrative records.
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Source: https://www.census.gov/retail/mrts/www/data/excel/19q2supptables.xls

5 Conclusions

A new supplemental quarterly e-commerce table was created and originally published as an 

experimental data product in response to data user requests for more frequent and more detailed 

measures of e-commerce sales on August 28, 2019. As of the 4th Quarter 2021 release on 

February 18, 2022, this table is now a standard data product. The Team creating the table 

encountered data suppression issues in creating a quarterly table to mimic the annual tables 

produced by the Annual Retail Trade Survey. Rather than publishing a table comparable to the 

annual table but with limited data, the Team created a new table layout that presents a whole 

picture of e-commerce sales by retailers’ kinds-of-business. Going forward, this table will be 

included in the Quarterly E-Commerce Report as a supplemental table.

In developing the new Table, the Team found that data users wanted a better understanding of 

how e-commerce sales are tabulated. In response, the Team developed a guide to help with this 

that is included as Appendix A. We also welcome feedback on improving this guide.
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Appendix A

As e-commerce has evolved over the past few decades, retailer operations around e-commerce

have evolved. As part of its outreach efforts regarding e-commerce, the Team realized that data 

users would like to better understand how individual retailers’ total sales and total e-commerce 

sales are tabulated and where that data is included in Census Bureau’s monthly, quarterly, and 

annual publications. This appendix first walks through how retailers’ retail and e-commerce 

operations are classified in the NAICS structure. Next, this appendix walks through how total 

retail sales and e-commerce sales tabulation parts are defined for retailers. And last, the appendix 

shows how these individual tabulation parts are included in the retail sales estimates published 

on a monthly, quarterly, and annual basis. 

To guide these explanations, three example retailers are used. These are simplified and 

hypothetical examples used to convey e-commerce sales survey reporting and tabulation 

scenarios. E-commerce operations and survey reporting arrangements can vary by retailer. These 

three example retailers represent the following three potential e-commerce operations scenarios:

• Single store location where e-commerce sales are fulfilled from within the store.

• Large retail chain with a separate e-commerce distribution center.

• Online retailer that has no brick and mortar presence and only operates online.
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• Retailer A is a small women’s clothing store. 

• Like other mom and pop style shops, Retailer A has only one 

store location. 

• Retailer A has a website that they conduct e-commerce on 

where all online orders are fulfilled from within the store.

• Retailer B is a women’s clothing chain with many store 

locations across the country. 

• Retailer B has a website for e-commerce. Online orders that 

are shipped are fulfilled from one distribution center.

• Retailer B offers the omnichannel e-commerce experience 

allowing customers to buy online and pick up in-store.

• Retailer C is a women’s clothing store that operates 

solely online (“pure play”).

Retailer Examples
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On its Economic Census form, Retailer A reported: • One physical store location operating in NAICS code 44812

(Women’s Clothing Store).

On its Economic Census form, Retailer B reported: • Multiple physical store locations operating in NAICS code 44812

(Women’s Clothing Store).

• One distribution center for e-commerce which is classified in

NAICS Code 45411 (Nonstore retailer).

On its Economic Census form, Retailer C reported: • One distribution center for e-commerce which is classified in

NAICS Code 45411 (Nonstore retailer).

Census Company Structure 
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Retailer A receives one MRTS form for retail activity in NAICS 44812 and • Reports Total Store Sales (equal to brick & mortar sales plus e-commerce

sales)

• Answers “yes” to the question “Did you have e-commerce sales this

month?”

• Reports Total E-commerce Sales (e-commerce sales only)

• Total E-commerce Sales should be less than or equal to Total Store

Sales

Retailer B receives two MRTS forms for retail activity in NAICS 44812 and 45411. 

On the 44812 form, Retailer B • Reports Total Store Sales equal to brick & mortar only • Reports zero for Total E-commerce Sales

On the 45411 form, Retailer B • Reports Total Store Sales equal to total e

-commerce sales.

• Reports Total E-commerce Sales.

• Total Store Sales equals Total E-commerce Sales unless there are

catalog or phone orders.

Retailer C receives one MRTS form for retail activity in NAICS 45411 and • Reports Total Store Sales equal to total e-commerce sales • Reports Total E-Commerce Sales • Total Store Sales equals Total E-commerce Sales unless there are

Company Reporting 

catalog or phone orders.
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Total Store Sales in NAICS 44812 

includes • Total Brick & Mortar sales • Total E-Commerce Sales

Total Store Sales in NAICS 44812 

includes • Total Brick & Mortar sales

Total Store Sales in NAICS 45411 

includes • Total E

-commerce Sales

Total Store Sales in NAICS 45411 

includes • Total E

-commerce Sales

Brick & 

Mortar Sales

(NAICS 

44812)

E-Commerce

Sales

(NAICS 

44812)

Brick & 

Mortar Sales

(NAICS 

44812)

E-Commerce

Sales

(NAICS 

45411)

E-Commerce

Sales

(NAICS 

45411)

Retailer Tabulation Parts
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Current Monthly 

E-Commerce Tabulations

B&M EC B&M

EC EC

EC EC
15

Quarterly E-Commerce Table

EC EC EC B&M EC B&M EC EC

Current Quarterly

E-Commerce Tabulations
16

Current Annual

E-Commerce Tabulations

Annual E-Commerce Table

B&M EC EC B&M EC EC EC EC

EC

B&M EC B&M EC

EC EC EC

EC EC EC EC
Current 

17

Annual Supplemental

E-Commerce Tabulations

Annual Supplemental E-Commerce Table

EC EC EC EC

EC

EC

EC

EC
18

Supplemental Quarterly E-Commerce Table

B&M EC B&M EC EC EC EC EC

EC EC

B&M EC B&M EC EC EC

B&M EC B&M EC EC EC

Supplemental Quarterly 

E-Commerce Table