WORKING 

PAPERS 

Dynamics in a Mature Industry: 

Entry, Exit, and Growth of Big-Box Retailers

Daniel Hanner 

Daniel Hosken 

Luke M. Olson 

Loren K. Smith 

WORKING PAPER NO. 308 

September 2011 

FTC Bureau of Economics working papers are preliminary materials circulated to stimulate discussion 

and critical comment. The analyses and conclusions set forth are those of the authors and do not 

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author to protect the tentative character of these papers. 

BUREAU OF ECONOMICS 

FEDERAL TRADE COMMISSION 

WASHINGTON, DC 20580
Dynamics in a Mature Industry: 

Entry, Exit, and Growth of Big-Box Grocery Retailers

Daniel Hanner 

Daniel Hosken 

Luke M. Olson 

Loren K. Smith1

U.S. Federal Trade Commission 

September 15, 2011 

Abstract 

This paper measures market dynamics within the U.S. grocery industry (defined as 

supermarket, supercenter and club retailers). We find that the composition of outlets 

changes substantially, roughly 7%, each year, and that store sizes have increased as the 

result of growth by supercenter and club retailers. We find significant changes in the 

relative position of brands in markets over time. These changes are largely the result of 

expansion (or contraction) by incumbents rather than entry or exit. There is little entry or 

exit, except by small firms. Moreover, only in small markets do entrants gain substantial 

market share. 

JEL Codes: D40, L4, L81 

Keywords: Antitrust, Entry, Expansion, Retailing, Supermarkets, Supercenters, 

Market Dynamics 

 

1

 We thank Christopher Adams for his help in getting this project started and Joseph Farrell, David 

Schmidt, Christopher Taylor, and Matthew Weinberg for comments. The views expressed in this paper are 

those of the authors and do not represent those of the U.S. Federal Trade Commission or any individual 

Commissioner. 
2

I. Introduction 

Entry and exit by firms are driving forces of economic growth and key elements 

of the competitive process. For example, recent research finds that virtually all of the 

labor productivity growth in the retail sector in the late 1990s was the result of entry and 

expansion of high productivity firms and the exit of less productive firms (Foster et al. 

2006). Antitrust authorities too have long recognized that entry into markets can play an 

important role in maintaining competition. The U.S. government’s primary policy 

document describing merger policy, the 2010 Department of Justice/Federal Trade 

Commission Horizontal Merger Guidelines, states that, “a merger is not likely to enhance 

market power if entry is so easy that the merged firm and its remaining rivals in the 

market, either unilaterally or collectively, could not profitably raise price or otherwise 

reduce competition.”2 However, determining whether entry would be easy and sufficient 

to replace the loss of competition resulting from a merger has proven to be difficult. 

Werden and Froeb (1988), for example, examine models with Cournot and Bertrand 

competition and find that with plausible levels of sunk costs that anticompetitive mergers 

are unlikely to generate entry. Further, for those cases where entry would occur 

following a merger, mergers would not be profitable unless they generated sufficient 

efficiencies such that the merger would not be anticompetitive to begin with. 

Notwithstanding this finding, courts have found that evidence of likelihood of entry into a 

market substantially lessens the concern that a merger in that market would be harmful 

(see, e.g., U.S. v. Syufy Enterprise (1990) and U.S. v. Baker Hughes (1990). 

 Surprisingly, given the importance of entry in antitrust analysis, there is relatively 

little detailed economic research examining market dynamics in the narrowly product 

categories which are often the focus of antitrust analysis.3

 To help fill this gap, our paper 

measures market dynamics during a recent six-year period (2004-2009) among three 

types of food retailers, traditional supermarkets, supercenters, and club stores that we 

 

2

 U.S. Department of Justice and Federal Trade Commission Horizontal Merger Guidelines (2010), Section 

9. 

3

 Notable exceptions are studies of the cement (e.g., Syverson (2008), airline (e.g., Goolsbee and Syverson 

(2008), and banking industries (e.g., Berger et al. (2004). 
3

refer to as the “big-box grocery retailing industry.” This industry is a particularly 

interesting and important industry in which to study entry. Retail markets are often 

viewed as markets in which entry and expansion should be relatively easy, and the threat 

of entry is often seen to be sufficient to maintain competition (U.S. v. Syufy Enterprise 

(1990)). Indeed, relative to some sectors, the requirements to enter a retail market are not 

particularly onerous. Retailers need to identify an effective location and obtain 

permission from local regulators to open an establishment. The sunk costs of entry (e.g., 

the cost of structures and permits), in particular, are likely much lower than in most 

industries. Notwithstanding the perceived ease of entry and expansion, mergers in retail 

markets are often subject to material antitrust review. Between 1998 and 2007, for 

example, the FTC investigated supermarket mergers affecting 153 antitrust markets and 

challenged mergers in 134 of those markets.4 Evidence on observed market dynamics in 

a retail market provides important information which can allow regulators to predict how 

likely potential entry or expansion by incumbents can be in lessening the competitive 

impact of mergers. 

 Our paper has four major findings. First, we examine changes in the composition 

of retail outlets in operation. While we find that the number of big-box grocery outlets 

operating in the U.S. has remained roughly constant at 31,000, each year roughly 7% of 

retail outlets either open or close. During our sample period, retailers operating club 

stores and supercenters have rapidly expanded at the expense of traditional supermarkets. 

However, even though the share of sales taking place at traditional supermarkets has 

declined, these retailers continue to open new stores each year representing roughly 2% 

of the stock of existing stores. We also find that while the average size of stores has 

increased over time, this change is largely the result of the expansion of retail formats 

using very large store sizes (club stores and supercenters) rather than an increase in the 

size of stores within formats. 

 Second, we examine entry by retail brands (defined as the operating name of the 

retail outlet such as Safeway or Albertsons) into new markets. We find that entry and exit 

are quite common for small independent supermarkets— single outlet firms—and 

 

4

 Horizontal Merger Investigation Data, Fiscal Years 1996-2007, Federal Trade Commission, Table 4-2. 

Available at http://www.ftc.gov/os/2008/12/081201hsrmergerdata.pdf. 
4

supermarkets owned by small chains (with less than 100 stores). Brand entry by chains 

operating large supermarket chains, however, is much more rare, and exit by large 

supermarket chains is three times as likely as entry (reflecting, in large part, the relative 

decline of traditional supermarkets). Entry by clubs and supercenters into non-rural 

markets is rare, however, this is largely a result of the fact that the firms operating these 

formats are already participants in most larger U.S. markets at the beginning of our 

sample period. In contrast to traditional supermarket retailers, we observe virtually no 

exit by firms operating clubs stores and supercenter retailers. We also find that other than 

in the smallest geographic markets, entrants rarely gain substantial (larger than 5%) 

revenue shares in the two years following entry. Thus, while entry is common for small 

firms, it is rare to observe entrants obtain a substantial share of industry revenue shortly 

after market entry. 

Third, we find that within market expansion and contraction by incumbent retail 

brands is responsible for more, often much more, of the change in the number of stores 

operated by retail brands than either entry or exit. Supermarket chains added 963 stores 

as the result of entry into new markets during our sample period while chains expanded 

operations in markets in which they already participated by 1,882 stores. Analogous to 

our findings with entry, during our sample we see club and supercenter retailers 

significantly expand their operations in existing markets and virtually never observe these 

retailers contract their operations. 

Finally, we examine the change in the relative size of market participants within a 

market over our sample period. We measure this “market churn” by taking the minimum 

of the aggregate net loss in establishments operated by shrinking brands and the 

aggregate net gain of brands that were expanding. We interpret this measure of turnover 

as the gain of growing brands that took place at the expense of shrinking brands. We find 

that most medium, large, and metro big-box grocery markets experience significant 

churn. For example, half of all metro markets experience banner churn of at least 11% 

between 2004 and 2009, that is, in these markets shrinking brands (collectively) shrink 

their operations by at least 11% (by closing stores) while expanding firms (collectively) 

expand their operations by at least 11%. 
5

Our paper adds to a recent and growing literature analyzing market dynamics in 

retail markets. These papers fall into two broad categories. Literature in the first 

category examines a broad set of retailers over time rather than focusing on a narrow 

class of retailers serving a single industry market. Foster et al. (2006) estimate 

productivity growth in the U.S. retail sector using data from three rounds of the U.S. 

Census of Retail Trade (CRT) (1987, 1992, 1997) and find that most productivity growth 

is the result of the expansion and/or entry of large efficient firms coupled with the 

contraction and/or exit of smaller inefficient firms. Haltiwanger et al. (2010) uses a very 

detailed dataset describing the location and employment of all retailers within the 

Washington D.C. metro area to examine how the entry of Big-Box retailers affects 

nearby competing retailers. They find that the effects of Big-Box competition are 

localized: small chains and independent retailers are most negatively affected if the 

entering Big-Box store is located close by and operates in the same detailed industry. 

Basker et al. (2010) study general merchandise retailers using seven waves of the CRT 

(1977-2007) and find that surviving retailers have grown substantially over time both by 

expanding the number of stores they operate and the types of products they sell. Finally, 

Kosova and LaFontaine (2010) examine the importance of firm size and age in predicting 

the survival and growth of a broad set of franchised retail chains. 

The second category focuses on competition among a narrow set of competitors 

like that analyzed in our paper. Many of these papers examine how WalMart’s rapid 

expansion as a mass-merchandiser and more recently as a grocery retailer affects labor 

markets (Basker (2005a) and Ciccarella et al. (2008)) and consumer prices (Basker 

(2005b), Basker and Noel (2009), and Hausman and Liebtag (2007)). Matsa (2009) 

finds that competing supermarkets lower their service levels (measured by likelihood of a 

stockout) in response to entry of a WalMart supercenter. Ellickson and Grieco (2011) 

estimate the impact of Walmart’s supercenter entry on the performance of nearby 

supermarkets. They find that rivals located nearby are negatively affected, mostly 

through an increase in the rate of decline of already weak firms. In contrast to the studies 

of WalMart supercenter entry, Courtemanche and Carden (2011) find that supermarkets 

do not lower their prices in response to club store entry. Instead, they find that entry by 

Costco supercenters is associated with an increase in supermarket prices while entry by 
6

Sam’s Club has essentially no impact on supermarket prices. Their finding is consistent 

with consumers that continue shopping at supermarkets having less elastic demand than 

those that shop at club stores. 

More generally, Ellickson (2007) and Igami (2011) study the supermarket 

industry in the U.S. and Japan. Using a cross-section of data from 1998 Ellickson 

measures market structure in local markets throughout the U.S. and concludes that the 

U.S. supermarket industry is best modeled as natural oligopoly. Igami (2011) examines 

how entry and exit decisions by incumbent supermarkets changed in response to a major 

change in Japanese retail deregulation which facilitated entry by large supermarkets in 

the greater Tokyo region. He finds that an entry by a large supermarket increases the 

likelihood of exit for large and medium incumbent supermarkets while it increases the 

survival rate for small supermarkets. 

 Finally, our paper contributes to the extensive literature on market entry.5 Klepper 

and Thompson (2006) develop a model which predicts that in mature markets, entry will 

take place in new segments (or submarkets) rather than in an existing technology. They 

provide empirical support for their model from the laser industry. Our finding that most 

entry and a large fraction of expansion in big-box grocery retailing, a very mature 

industry, is driven by retailers offering relatively new differentiated products (club stores 

and supercenters) aligns with Klepper and Thompson’s predictions. 

The remainder of the paper is organized as follows. Section II describes the 

retailers we are studying, and the construction of the markets they compete in. Section 

III describes our data source and Section IV presents our results. Section V concludes. 

II. Institutional Background 

We limit our attention to large grocery retailers that sell food and other household 

goods, e.g. cleaning products, where consumers can purchase all of their food for a week 

at a single retail location (often referred to as offering one-stop-shopping). This 

definition yields a market we refer to as “big-box” grocery retailers consisting of three 

 

5

 See Geroski (1995) for a detailed literature review and Baker (2003) for a discussion of the recent 

treatment of entry in Horizontal Merger analysis. 
7

different retail formats: traditional supermarkets, club stores, and supercenters. Our 

market excludes a number of retail formats that carry but do not specialize in selling food 

and other household goods, and firms that specialize in food but do not offer one-stopshopping. Drug stores, convenience stores, and traditional mass merchandisers (nonsupercenter outlets of firms such as Target, Kmart, and WalMart), for example, only offer 

a limited selection of food items and offer few of the perishable items which most 

consumers purchase weekly such as fresh meat and produce. These different retail 

formats are likely distant substitutes to big-box food retailers, and their exclusion is 

therefore unlikely to mask important industry dynamics.6 

A traditional supermarket is defined as a self-service retailer selling a full line of 

food products (including grocery, meat, and produce).7 There is substantial variation 

across geographic markets in establishment size, services offered, and the number of 

retail outlets operated by a supermarket firm. Not surprisingly, population density and 

the price of land are important in determining the size of supermarkets. In old, densely 

populated urban areas supermarkets are small, often with less than 20 thousand square 

feet of grocery selling space, while in newly developed suburban areas, supermarkets can 

be enormous (with grocery space and total selling space of 80 and 100 thousand square 

feet, respectively). As supermarkets expand in size they often increase the products and 

services available in the store including pharmacies, in-store bakeries, full-service delis, 

extensive wine and beer selections, bank branches, and even dry cleaners. 

Following the recent literature which examines dynamics by firm size, e.g., Foster 

et al. (2006), we have divided our supermarket sample into three groups based on firm 

size: independents (1 store), small chains (between 2 and 100 stores), and large chains 

 

6

 Previous empirical work discussed above shows that supermarkets change their prices in response to 

competition from supercenters and club retailers suggesting that these retail formats compete with one 

another. We are unaware of empirical work that directly measures substitution between big box grocery 

retailers and other types of food retailers. We do note that in its investigations of supermarket mergers the 

Federal Trade Commission (FTC) has typically concluded that competition among supermarkets is 

primarily limited to other supermarkets. For example, in its complaint challenging the merger of A&P and 

Pathmark in 2007, the FTC stated “Retail stores other than supermarkets that sell food and grocery products 

including neighborhood “mom & pop” grocery stores, convenience stores, specialty food stores, club 

stores, military commissaries, and mass merchants do not individually or collectively effectively constrain 

prices at supermarkets.” See” Complaint in the Matter of The Great Atlantic and Pacific Tea Company 

INC., a corporation and Pathmark Stores Inc., a corporation” available at 

http://www.ftc.gov/os/caselist/0710120/0710120cmplt.pdf. 

7

See the Food Marketing Institute’s Supermarket Facts available at: 

http://www.fmi.org/facts_figs/?fuseaction=superfact. 
8

(with more than 100 stores). 8 While these groups are somewhat arbitrary, the sample is 

divided fairly evenly with 29% of stores operated by independents, 25% of supermarkets 

owned by small chains, and the remaining 46% of supermarkets owned by large chains. 

 Supercenters are an important and rapidly growing big-box grocery retail format. 

Supercenters are typically larger than 180,000 square feet, combining both a large 

supermarket and a large mass-merchandiser within the same store. The most well-known 

supercenter retailer, Wal-Mart, opened its first supercenter in 1988 and is now the U.S.’s 

largest food retailer.9

 

The third big-box grocery retail format is the club store. Club stores are high 

volume retailers that typically charge members an annual fee and offer a limited selection 

of a broad variety of products, including food items, usually in relatively large packages 

at significant volume discounts. A key difference between club stores and traditional 

supermarkets or supercenters is product selection; supermarkets or supercenters typically 

carry between 45,000 and 140,000 items while a club store may stock less than 4,000 at 

any point in time.10 Despite their limited product offerings, club stores sell food in a 

large number of food categories, including meat and produce, and likely offer consumers 

the opportunity to purchase all of their food items at a single outlet; that is, a club store 

offers something very close to one-stop-shopping. According to Costco’s 2009 Annual 

Report, 33% of Costco’s sales were of food items with 12% of total Costco sales being 

Fresh Food items (including meat, bakery, deli, and produce). Given the very large sales 

volume of club stores (the average Costco outlet has $131 million in annual revenue), a 

typical club store sells more food items in a week than a very large traditional 

supermarket. 

 Table 1 provides some descriptive information about the establishments operating 

in the big-box grocery retail industry by format. The first 7 columns of Table 1 provide 

information on the distribution of estimated weekly grocery sales (in thousands of 

dollars) while the next seven columns describe the amount of selling space devoted to 

grocery items for the different firms operating in big-box grocery retail. Clearly, 

 

8

 We define firm size as the total number of supermarket, club, and supercenter outlets operated by the 

firm. 

9

 Supermarket news list available at: http://supermarketnews.com/sndata/. 10 Costco 2009 Annual Report, page 9. 
9

traditional supermarkets are much smaller retailers than either supercenters or club stores. 

The largest supermarkets (the 90th percentile of the large chain distribution is roughly 

$475 thousand per week) have similar estimated weekly sales than the smallest club 

stores and supercenters (the 10th percentile is $625 and $425 thousand per week, 

respectively). Supermarkets in large chains are both larger and have greater revenue, on 

average, than supermarkets in small chains, although there is considerable overlap in the 

two distributions. In contrast, independents are much smaller and have much lower 

revenue than either large or small supermarket chain outlets. Finally, supermarkets in 

large chains appear somewhat more homogeneous than those in small chains: both the 

standard deviation of store size and estimated weekly establishment sales are smaller for 

large chains than small chains despite a significantly larger mean. 

Market Types 

In order to define market entry and exit we must first define the geographic 

regions in which firms in the big-box grocery retail industry operate.11 Unfortunately, 

market definition is not obvious and very different approaches have been taken in the 

literature. Many studies which focus on localized competition between retailers use 

relatively small geographic market definitions such as a county. This definition is 

reasonable when using a demand-side definition of a market: consumers do not travel far 

to purchase food and are likely most familiar with the retailers in operation near where 

they live and work. Empirical work suggests that localized competition is relevant in 

affecting supermarket pricing (See e.g., Basker and Noel (2009)). A very narrow 

geographic market definition, however, ignores commercial connections with 

surrounding counties that affect firm store opening and closing decisions. Therefore a 

more expansive definition of geographic markets may be appropriate for explaining a 

firm’s decision to incrementally expand the size of its chain. For example, a supermarket 

chain that is present only in Los Angeles County, California will be more likely to open a 

 

11 We are not attempting to construct antitrust markets (product and geographic) like those described in the 

Horizontal Merger Guidelines. Instead, as we describe in great detail below, we are focusing on 

identifying the set of similar retailers providing similar retail services (big-box-grocery retailing) and the 

geographic regions in which the firms either currently operate stores or could readily expand. In most 

cases, antitrust markets are likely smaller than the markets we consider here. 
10

new establishment in Ventura County, California than in Fairfax County, Virginia.12 

Consumers in Ventura County will likely be familiar with the brand name of the Los 

Angeles based chain, a distribution network is already present, and experienced 

employees may be transferred to the new store without the various costs of relocation. 

Ellickson (2007), for example, defines the geographic regions in which retailers compete 

by focusing on the supply side: the distribution area used by supermarkets (corresponding 

to the region that stores can be served by a single distribution center). Ellickson argues 

that this definition is appropriate because firms can expand their operations within these 

broad regions with relatively little additional fixed or sunk costs and so it better reflects 

the level at which the firm is operated. Using this definition, Ellickson divides the U.S. 

into 51 geographic markets. 

Our goal is to define markets that divide the U.S. into a series of mutually 

exclusive and completely exhaustive regions where each region is composed of political 

regions (counties) that share important commercial connections. By defining markets 

using commercial connections we incorporate the demand and supply concepts used in 

previous work in defining local retail markets. This is the approach taken by the Office 

of Management and Budget (OMB) in its construction of regional markets. We use two 

OMB geographic designations to construct these markets – Core Based Statistical Area 

(CBSA) and Combined Statistical Area (CSA). A CBSA is defined as a set of adjacent 

counties connected to a common urban core of at least 10,000 residents by commuting 

ties. A CSA is a consolidation of contiguous CBSAs that have a weaker but still 

significant employment interchange. 13 The rule we used in constructing geographic 

markets was to create the largest connected region. That is, if a store is in a county that 

belongs to a CBSA, the market for that store was defined to be at least as big as that 

CBSA, while if a store is located in a CBSA that belongs to a CSA, then that store’s 

market is the CSA. 

The result is a set of geographic markets that are mutually exclusive, cover the 

entire United States, and that represent regions that are economically connected to each 

 

12 As empirical support for this intuitive claim, we later show that large chain retailers are much more likely 

to open stores within a metro region they currently operate in than in a new metro region. 13 The official standards for defining these areas are available at the OMB website. See: 

http://www.whitehouse.gov/sites/default/files/omb/fedreg/metroareas122700.pdf 
11

other.14 These geographic markets may consist of a single county or as many as 33 

counties. The typical number of counties in a market is small, the median being 1 and the 

95th percentile being 4. The median population for a market consisting of a single county 

is 10,627. The market with the largest population in our data, New York-Northern New 

Jersey-Long Island, NY-NJ-PA, consists of 30 counties. 

In presenting our results we have grouped these geographic markets into four 

categories based on estimated population: Rural/Small City, Medium City, Large City, 

and Metro. Rural/Small City market corresponds to any market with a population under 

100,000; Medium City corresponds to a unit for which the population is at least 100,000 

but less than 1,000,000; Large City corresponds to a unit for which the population is at 

least 1,000,000, but less than 5,000,000; while Metro corresponds to a unit for which the 

population at least 5,000,000. While these break points do not evenly divide the U.S. 

population, they divide regions of the U.S. into meaningful groups with similar levels of 

population density. 

 Table 2 presents the number of markets of each type we study and describes the 

mean number of stores and revenue share for each retailer type for each of the four types 

of geographic markets we study.15 We categorized 1,593 markets as Rural/Small City 

that collectively account for 12.7% of the U.S. population. The mean Rural/Small City 

market has 1.2 independent supermarkets, 1.04 small chain supermarkets, and 0.88 

supermarkets owned by a large chain. While Club stores are very rare in Rural/Small City 

markets (0.02), these markets have 0.42 supercenters on average. Not surprisingly, the 

number of stores in markets increases dramatically as the market size grows. It is worth 

noting that the type of ownership of supermarkets also appears to be related to market 

size. In Rural/Small City and Medium City markets, independent and small chain 

supermarkets are relatively common while in Large City and Metro markets 

supermarkets owned by large chains make up a much larger fraction of total 

establishments within a geographic market. 

 

14 While all of the counties were included in the classification process, only geographic units for which at 

least one store was in operation at the beginning of the period were included in the analysis. 

15 The mean number of stores in a market type is calculated by counting the number of stores in each 

market and year by store type. These counts are then averaged by market type. The mean market share is 

calculated in a similar manner by summing the revenue of all stores in a particular store type for each 

market and year and then averaging by market type. Markets with 0 stores of a particular store type in a 

given year were counted as having 0 stores and having 0% share in that year. 
12

III. Data 

Our primary dataset comes from A.C. Nielsen’s Trade Dimensions retail 

database. Each year, the firm creates a census of all retail outlets in the U.S. for a number 

of retailing industries including, for example, supermarkets, club stores, liquor stores, 

convenience stores, and restaurants. We have obtained data for conventional 

supermarkets, supercenters, and club stores.16 Our dataset consists of annual 

observations including the location, size, estimated sales, a unique store number, the 

owner of the store, and estimated number of employees of each supermarket, supercenter, 

and club store in the U.S. from 2004 through the fall of 2009. A nice feature of the 

dataset is that every store location has a unique identification number that allows us to 

track stores over time. For example, we can observe if a location changes ownership or 

whether a supermarket that closes for a time and reopens as another supermarket. 

Additionally, the dataset contains information on the ownership of different chains which 

is important because many firms operate multiple retail brands, sometimes even within a 

relatively small geographic area. 

We have also obtained annual county-level information from the Census 

including population estimates that allow us to construct and categorize the geographic 

markets in which the firms compete. 

IV. Results

 In this section we present the paper’s empirical findings. First, we show that 

while the number of retail outlets operated in the big-box grocery industry has remained 

relatively constant in our sample period, there is significant turnover in the physical 

outlets operating within the industry each year. Some of this turnover is the result of a 

major change taking place within food retailing: the relative decline of traditional 

supermarkets and growth of club and supercenter retailers. Despite this ongoing trend, 

we observe a large number of both store closings and openings of supermarkets. We next 

 

16 We exclude other retail formats in the Trade Dimensions Grocery data set – limited assortment, 

natural/gourmet food, warehouse, and military commissary – because they are so differentiated from 

traditional supermarkets. For example, of these retail formats, only military commissaries offer one-stopshopping. However, military commissaries are available to only a subset of the population. 
13

develop some stylized facts describing within market dynamics. We find that market 

entry and exit by independent supermarkets and supermarkets operated by small chains is 

relatively common but that entry by large chain retailers is considerably rarer. Further, 

other than in relatively small markets, entrants rarely gain significant revenue shares 

within two years of market entry. We also find that market expansion and contraction by 

incumbent brands is responsible for more within market growth (contraction) than either 

entry or exit. Finally, we measure the change in relative market share- within market 

gains by expanding firms and contraction by shrinking firms, and find evidence that the 

relative position of retail brands changes significantly in many markets during our sample 

period. 

Changes in the Composition of Retail Outlets 

We begin by presenting a simple count of the number of retail outlets operated 

each year for each of the five retailer types (Table 3). In Table 3, we see that the number 

of retail outlets in the industry has been relatively constant, at roughly 31,000, between 

2004 and 2009. This aggregate stability masks a significant change in the composition of 

retail outlets being operated over time. During our sample period the number of outlets 

operated as supermarkets declined by roughly 5% while the number of supercenters and 

club outlets expanded by 53.1% and 16.4%, respectively. Similarly, as shown in Figure 

1, we see the revenue received by supermarkets has declined substantially, from 66.6% to 

57.6%, while revenue shares for supercenters and clubs increased over the period – from 

21.1% to 29.4% and from 12.3% to 13.0%, respectively. 

While some of the changes in the composition of retail outlets operated in the 

U.S. are caused by the relative expansion of club and supercenter retailers, we also 

observe considerable turnover among the stores operated as traditional supermarkets. To 

show this we measure the number of store openings and closings for each retailer type. 

We define a store opening in year t as a new store location appearing in our dataset for 

the first time in period t. A store closing in year t is defined as a store that was present in 

year t-1 disappearing from the dataset in year t.17 Figure 2 shows the overall rate of 

 

17 In a small number of cases a store disappears from the data for one or more periods and later reappears 

with the same store name. This event is likely either the result of a long-term store remodeling or, possibly, 
14

openings and closings for the years 2005 through 2008 relative to the total number of 

stores operated within each retail format.18 We see that across retailer types, turnover is 

substantial. Conventional supermarket retailers both opened and closed between 2-3% of 

their stores each year, with store closings being more common than openings during the 

sample period. In contrast, supercenter and club store retailers frequently open new 

stores (supercenters increased their stock of stores by more than 10% in 2005 and 2006) 

and almost never close existing stores. 

 Having established that retailers frequently open and close stores, we now 

examine how three characteristics of stores (size, revenue, and labor productivity) differ 

among newly opened, closed, and continuously operated retail outlets. Table 4 presents 

the mean size of the retail outlet store devoted to selling grocery items (thousands of 

square feet of grocery selling space), the estimated weekly sales of grocery items, and an 

outlet’s estimated total weekly sales per employee separately for independent 

supermarket, chain supermarkets, supercenters, and club stores.19 We find that for most 

store categories, store performance (measured as grocery revenue or total revenue per 

employee) is greatest for continuing stores and smallest for exiting stores. Stores that 

operate continuously are larger on average than either those that are being opened or 

closed throughout the sample period. For chain supermarkets and club stores, newly 

opened stores are of very similar size as closing stores, suggesting that store locations or 

possibly firms are being replaced rather than changes in the breadth of product offerings 

within a store. In contrast, the average opening supercenter outlet is 12.5% larger than a 

closing supercenter outlet. Finally, newly opened supermarkets operated by independents 

are 14.0% smaller on average than closing stores. 

 measurement error in the dataset and is not categorized as either a store opening or closing. Store locations 

that change ownership, e.g., assets that change ownership as the result of a merger or acquisition, are not 

categorized as either store openings or closings. 18 To be more precise, the graph shows the number of opened stores in the year (openings) and the number 

of stores that are in operation, but will not be in operation in the next year (closings) divided by the number 

of stores of a particular format in operation in that year (total number of stores). 

19 Trade Dimensions reports an estimated number of employees for the outlet; that is, both employees 

selling grocery items and non-grocery items. For this reason, we calculate worker productivity as the ratio 

of total sales (both grocery and non-grocery items) per employee. For traditional supermarkets grocery 

sales make up the majority of sales, however, for club and supercenter outlets grocery sales are less than 1⁄2 

of total sales. Club stores do not have reliable employee counts, and so are excluded from this calculation. 
15

 The results in Table 4 describe how new, closed, and continuously operated stores 

compare throughout the U.S. without controlling for market type (rural or metro markets) 

or firm. Store size and revenue, however, vary significantly across both retail firms and 

markets. To examine how opening, closing, and continuously operated stores compare 

holding these factors fixed, we have estimated equations (1)-(3) below separately for 

chain supermarkets, club stores, and supercenters where in each equation i denotes the 

store, j the chain, and k the market that store is located in. Each estimating equation 

includes controls for market type (medium markets, large markets, and metro markets) 

and separate indicator variables for each chain owner.20

l

ijk ijk ijk l ijk

l

j

j ijk ijk

j

l

ijk ijk ijk l ijk

l

j

j ijk i

(1)log(Weekly Grocery Revenue) =a+bOpening +cClose + δ Market Type

θ Chain +e

Total Weekly Revenue (2)log( ) =a+bOpening +cClose + δ MarketType Total Employees

+ θ Chain +e









jk

j

l

ijk ijk ijk l ijk

l

j

j ijk ijk

j

(3)log(Grocery Square Feet) =a+bOpening +cClose + δ MarketType

+ θ Chain +e







For independent supermarkets it is not possible to control for the firm owner (since each 

firm owns a single store), so we estimate variants of equations (1)-(3) which do not 

include the chain indicators. Standard errors are calculated clustering at the market (k) 

level. For brevity we only report the coefficients corresponding to the opening and 

closing indicator variables in Table 5 (i.e. b and c in equations (1)-(3)). 

Controlling for a store’s chain and market type, we find the same general pattern 

seen in the unconditional means. Exiting stores tend to be the smallest and have the 

lowest revenue across retailer types, and newly opened stores are smaller and have lower 

revenue than continuously operated stores. The results for worker productivity 

(measured by total revenue per employee) are somewhat different. As before we find 

that exiting stores owned by chain supermarkets and supercenters are less productive than 

 

20 The omitted categories are continuing stores and rural stores. 
16

both newly opened stores and continuously operated stores controlling for the chain 

owner and the market type. For chain supermarkets, however, newly opened stores are 

slightly more productive (roughly 1%) than continuously operating stores. More 

surprisingly, exiting independent supermarkets have virtually the same productivity as 

continuing supermarkets, while newly opened independent supermarkets are the most 

productive.21

Entry and Exit 

There are many potential definitions of entry into a retail market. For instance, 

one of the primary factors differentiating competing retailers is the locations of the 

retailers’ stores. When a retailer operating in a city opens up a store in a new 

neighborhood some consumers who had not previously considered the retailer as an 

option now consider the retailer as being in the choice set. In this sense, expansion 

within a broader geographic market could be viewed as market entry. 

Operators of chain supermarkets often enter a region by purchasing an existing 

retailer and continuing to operate stores in that region under that retailer’s brand name. 

Ahold, one of the largest U.S. operators of chain supermarkets in the U.S., does not 

operate any stores in the U.S. under its corporate name. Over time, Ahold has purchased 

supermarket chains such as Stop-and-Shop in the Northeastern U.S. and Giant 

Supermarkets in the Mid-Atlantic region, while maintaining their existing brand names. 

Although acquisitions of this type clearly represent a change in corporate control and the 

entry of a new firm (rather than a brand) into a region, the set of products available to 

consumers (brand names of retailers) do not change as the result of the transaction. 

 We study two types of entry which result in consumers being offered a new retail 

brand.22 The first type of entry we define as “new firm entry” where a 

a firm with no presence in a market introduces a new brand to that market. The second 

type of entry is “banner entry” where an incumbent firm introduces an additional brand to 

that market. For example, during our sample period Delhaize began opening 

 

21 In their study of worker productivity of U.S. retailers Foster et al. (2006) found that continuously 

operated stores were the most productive followed by newly opened stores and that exiting stores were the 

least productive. 

22 Entry defined in this manner has been the topic of a number of recent retail studies focusing on entry by 

“big box” chains such as Walmart (e.g, Foster et al. (2006), Basker (2005), and Ciccarella et al. (2008)). 
17

supermarkets operated as Bloom, a more upscale version of its traditional Food Lion 

supermarkets.23 This type of entry is very different than new firm entry. While 

consumers are being introduced to a new product, the number of independent price 

setting firms has not increased. Banner entry is best viewed a form of new product 

introduction by incumbent firms, see e.g., Schmalensee (1978). Our definition of entry 

does not therefore include the sale of a local brand to a new firm that continues to operate 

retail outlets under the same trade name, such as the Ahold example discussed above. 

We also do not consider within market expansion – an existing retailer opening new 

stores of an existing banner in a market – to be entry.24 We examine within market 

expansion and contraction in detail below. 

We define exit as an event that causes consumers to lose access to a brand in a 

market. As with entry we consider two types of brand exit. We define “firm exit” as an 

event where both the firm and retail brand exit a market. We define a “banner exit” as an 

event where a retailer discontinues one of its retail brands but maintains its presence in 

the market as a big-box grocery retailer. Delhaize, for example, recently announced it 

will convert all but one of its Bloom stores in North and South Carolina to Food Lion 

stores.25 Those markets that saw the conversion of Bloom stores to Food Lion as markets 

experienced banner exit. Parallel to entry, we do not view the sale of a retail brand to 

another corporate parent as brand exit if the subsequent owner continues to operate at 

least one store in an affected market under the original retail banner. Similarly, if a firm 

closes some but not all of the stores operating under a given banner we consider this to be 

within market contraction and not exit. 

Panel A of Table 6 presents estimates of the overall rate of brand entry (defined as 

both firm entry and banner entry) including the mean number of entry events for each 

type of retailer and geographic market, the total number of entry events for each retailer 

type, and the total number of stores involved in entry between 2004-2009. We see that 

brand entry is relatively common among smaller firms. Roughly 63% of all entry events 

 

23 Supermarket News, March 14, 2011. 

24 As noted earlier, the geographic markets used in antitrust analysis are frequently more narrow than the 

geographic regions we have defined to be markets. As a result, what we define as a market expansion (e.g., 

a brand with operations in Los Angeles opening a store in Ventura) might be interpreted as market entry in 

an antitrust analysis (if Los Angeles and Ventura were separate antitrust markets). 25 Supermarket News, 3/11/2011. 
18

(1,605) are by independent supermarket firms.26 The average medium sized city, for 

example, experiences 1.45 entries by new independent firms while metro markets 

experience, on average, 57 entries by independent supermarkets. Brand entry by small 

chain supermarkets is also common, with roughly 3.58 entry events in the average metro 

market, but less frequent than the entry of independents. Entry by large supermarket 

chains is much rarer. Large city and metro markets, on average, experienced only 0.83 

and 0.68 entry events by large supermarket chains. Entry by supercenter and club 

retailers is also relatively unlikely in medium, large and metro markets. However, the 

reason entry is infrequent is because only a small number of firms operate these formats, 

and these firms were already operating in most large cities and metro areas by the 

beginning of 2004.27 Finally, while entry of supercenters into rural/small city markets is 

relatively rare – the mean market experienced only 0.14 entry events – most supercenter 

entry occurred in these markets (223 of 247 entry events). 

Panels B and C provide a breakdown of brand entry separately for firm entry and 

banner entry. By comparing Panels B and C, we see that small chain supermarkets, club 

stores, and supercenters are much more likely to begin operating a new brand in a market 

as a result of firm entry than by banner entry. For example, consumers in metro markets 

are about twice as likely, on average, to observe a new brand operated by a small 

supermarket chain entering a market (2.5) than to see an incumbent chain begin operating 

a new banner (1.08). In contrast, brand entry by large supermarket chains in metro and 

medium markets is, on average, about as likely the result of firm entry as incumbent 

firms introducing a new banner. For club and supercenter firms, most of banner entry is 

the result of WalMart opening Sam’s club stores in markets where it is already operating 

supercenters or the reverse. 

Table 7 presents the total number of brand exit events and the mean number of 

brand exit events by retailer and market type for all exits (Panel A), firm exits (Panel B), 

and banner exits (Panel C). As with entry, brand exit from a market is most common for 

independent and small chain supermarkets (rows 1 & 2 of Panel A). Brands operated by 

 

26 Recall that by independent firms operate a single retail outlet so that, by construction, for independent 

firms brand and firm entry are equivalent. 

27 Three retail brands (BJs, Costco, and Sam’s Club) account for 99.3% of clubs stores and three brands 

(WalMart, Target, and Meijer) account for 93.2% of supercenters in 2008. At least one supercenter was 

operating in 11 of the 12 metro areas and in 39 of the 40 large cities at the beginning of the time period. 
19

large chain supermarket retailers, however, are much more likely to exit than enter during 

our sample period. The mean metro market sees 1.75 brands operated by a large chain 

exit and only .83 brands enter. Further, brand exits by both large and small chain 

supermarkets involved many more stores than brand entries. The 219 entry events by 

large supermarket chains involved 473 stores while the 408 exit events involved 1117 

stores. In contrast, exit by supercenter and club retailers were extremely rare. During our 

sample period we observed only 1 exit by a club retailer and 10 exits by supercenter 

retailers. 

Panel B and Panel C of Table 7 disaggregate the statistics describing brand exit 

separately for firm exit and banner exit, respectively. There are two key findings from 

these breakdowns. First, market exit by small and large chain supermarkets is a much 

larger source of brand exit (1343 stores) than firms discontinuing one of multiple retail 

brands operated in a market (477 stores) during the sample period. Clearly, this is a 

period where small and large chain supermarkets are abandoning many of the markets 

they operate in. In contrast, brand entry by chain supermarkets is much more balanced 

between firm entry (460 stores) and banner entry (506 stores). Second, banner entry 

(Table 6 Panel C) and banner exit (Table 7 Panel C) appear similar for chain 

supermarkets; that is, firms seem to either add or subtract retail banners within the 

markets they operate with similar frequency. 

Significance of Entry 

 Having measured the frequency of entry, it is natural to next measure the 

economic importance of entry. While an entrant could have many effects on a market 

(reducing prices, causing exit, increasing variety), we focus on measuring the size of an 

entrant brand after two years of market participation. Specifically, for each entering 

brand we calculate its revenue share by summing over all stores opened under that brand 

name in a market in the second year following the brand’s entry.28 

Figure 3 plots the 25th, 50th, and 75th percentiles of the distribution of the markets 

share of firm entrants calculated separately for each combination of retailer/market type. 

 

28We have also estimated the size of entering brands in the first and third year following entry and find very 

similar results to those shown in Figures 3 and 4. 
20

Figure 3 shows that all retailer types frequently attain significant revenue share in 

rural/small city markets in the two years following entry. For example, entering 

supermarkets owned by independents in the 25th, 50th, and 75th percentile of the market 

share distribution attain a market shares of roughly 4%, 7%, and 21%, respectively (top 

panel of Figure 3). Entering supermarkets owned by either small or large supermarket 

chains appear to gain larger market shares, with a median market share of roughly 14%. 

In rural markets, clubs and especially supercenters can attain very large market shares. 

The median supercenter in a rural/small city market attains an estimated revenue share of 

nearly 60%. Outside of rural markets, however, entrants rarely attain significant market 

shares in the two years following entry. In large city and metro markets we never 

observe the 75th percentile of the market share distribution rising above 7%. In medium 

markets we periodically observe supercenters become relatively large (the 75th percentile 

is roughly 16%). Hence, while we see that firm entry is relatively common, outside of 

the smallest markets, firm entrants rarely obtain significant revenue shares in the first 

years following entry. 

New retail brands introduced by incumbent retailers attain revenue shares similar 

to de novo entrants in the two years following entry. This can be seen by comparing 

Figure 3 with Figure 4 which plots the 25th, 50th, and 75th percentiles of the market share 

distribution for incumbent firms chain engaged in banner entry. In rural/small city 

markets the median revenue shares for small and large chain supermarkets and club 

stores are very similar in Figures 3 and 4, roughly about 15% and 19% for small and 

large chain supermarkets and 18% for club stores. The revenue shares of “banner 

entrants” are even more similar to firm entrants in larger markets. In large and metro 

markets banner entrants very rarely attain market shares larger than 5%. The only 

significant difference in the market impact of firm and banner entrants is seen for 

supercenter entrants in rural/small city markets. While supercenter brands introduced by 

an incumbent retailer (most frequently WalMart) still attain substantial revenue share 

within the two years following entry (the median is larger than 30%), the distribution of 

revenue share for supercenter firm entrants is shifted significantly to the right of banner 
21

entrants (with a median revenue share of 60%). Again, we conclude that outside of the 

smallest markets, entrants rarely obtain substantial revenue shares.29

Changes in Store Composition within Markets 

The entry and exit of a retail brand is not the only process that changes the set of 

retailing options available to consumers. Firms operating retail brands often expand or 

contract their operations within a market. This within market expansion and contraction 

by incumbent retail brands is responsible for more, often much more, of the change in the 

number of stores operated by brands within a market than either entry or exit. Our goal is 

here is to measure how much expanding brands grow and contracting brands shrink 

within the markets they operate during our sample period. To do this we first categorize 

each brand as either expanding (increasing the number of stores in operation), contracting 

(decreasing the number of stores in operation), or unchanged for each market and time 

period they are market participants. We then measure total expansion within a market in 

a time period as the number of stores added by expanding retail brands operating in that 

market in that time period. Similarly, aggregate contraction in a market is defined as the 

sum of all net reductions in the number of stores operated by contracting retail brands in a 

market in period t. 

Table 8 presents the total number of stores added by expanding brands, and the 

mean number of stores added by expanding brands by retailer and market type. We see 

that market expansion is common and often results in significant growth by expanding 

brands within a market. The mean metro market, for example, saw expanding club 

retailers add 4.5 stores. In the average large city market expanding small and large chain 

supermarkets added 5.3 and 11.33 stores, respectively. To scale the relative importance 

of within market expansion reported in Table 8, we have calculated the number of stores 

added to markets as the result of both firm and banner entry in Table 9.30 Comparing 

Tables 8 and 9, we see that in all but the smallest sized markets, within market expansion 

by incumbent retailers is much more important than entry in accounting for aggregate 

 

29 Our findings do not imply that entry does not have localized effects. Entrants almost certainly obtain a 

much larger revenue share within neighborhoods in which their establishments are located. Instead, our 

results show that outside of the smallest markets entrants rarely obtain significant revenue shares within 

two years in the relatively broad geographic markets we have defined. 

30 The store counts in Table 9 correspond to the entry events presented in Panel A of Table 6. 
22

within market brand growth. For instance, in the average metro market growth resulting 

from entry of brands operated by large supermarket chains resulted in the addition of 10 

stores while expansion by incumbent chains resulted in 24.25 new stores. 

 Similarly, within market contraction accounts for a large fraction of the reduction 

in the number of stores operated by brands within a market. However, as we show below 

the relative importance of contraction and exit is far more similar than expansion and 

entry in explaining brand growth. Table 10 presents the average number of stores closed 

by incumbent retailers in different sized markets during our sample period. As with exit, 

we see that within market contraction by club and supercenter retailers is quite rare (only 

9 supercenters and 10 club outlets were closed by incumbent firms throughout the U.S.). 

Contraction by brands operated by small and large chain supermarket retailers were much 

more common. The average metro market saw 23.5 and 38.5 stores closed by contracting 

small and large chain supermarkets. To compare the relative importance of exit and 

contraction in explaining within market changes in the size of brands, we have calculated 

the average number of stores closed as the result of exit by retailer and market type 

during our sample period (Table 11).31 In comparing Tables 10 and 11, we see that 

within market contraction is responsible for more store closures than exit by chain 

supermarkets in large city and metro markets. In the average large city market 

contracting brands operated by small and large chain retailers closed 4.3 and 10.3 stores 

while brands operated by exiting small and large chain supermarkets closed 2.28 and 8.1 

stores. In medium sized markets, however, store closures caused by within market 

contraction are nearly the same as those caused by exit for chain supermarkets. 

Within Market Changes in the Size of Retail Brands 

We have shown that between 2004 – 2009 the number of retail outlets operated by 

big-box food retailers has remained roughly constant while relatively new retail formats, 

clubs and supercenters, have grown at the expense of traditional supermarkets. We have 

also shown that within market expansion and contraction by chain supermarkets explains 

a larger fraction of within market brand growth than either market entry or exit. In this 

 

31 The store counts in Table 11 correspond to the exit events presented in Panel A of Table 7. 
23

section of the paper we construct two measures of market churn that describe how much 

the relative size of market participants changes within a geographic market between 2004 

and 2009. The first measure focuses on changes that are most apparent to consumers: the 

change in the relative number of stores operated by retail brands (WalMart, A&P) that 

consumers observe in a geographic market. These changes are the result of both the 

expansion or contraction of incumbent brands and the entry and exit of new brands. The 

second measures the change in corporate ownership of outlets within a market which 

includes the entry of firms operating within a market as well as the sale of retail brands to 

different corporate parents. During our sample period a number of major food retailers, 

including Ahold and Albertsons, spun off large local brands to new firms. While these 

changes represented large changes in corporate control, they likely were transparent to 

consumers who observed the same brands operating in their local market. 

We first measure churn in the number of stores operated by different brands 

within geographic markets during our sample period (2004-2009). We define churn as 

the amount of local market share (measured by retail locations) that changed hands 

among market participants (including entering or exiting brands). We begin by 

calculating each brand’s (i) net growth in market j (brand growthij) as the difference in 

the number of stores it operated in 2009 and 2004 (where brandij2009 is the number of 

stores operated by brand i in market j in 2009): 

2009 2004 . ij ij ij brand growth brand brand  

Within market j, we group brands into those that were shrinking (brand growthij <0) and 

growing (brand growthij >0) and then calculate the total number of stores that were added 

by growing brands or eliminated by brands that were shrinking. Because we are 

interested in measuring changes in the relative size of brands independent of changes in 

overall market size, we measure within market changes in relative size as the minimum of 

the proportional change in the number of stores either operated by growing or shrinking 

brands; that is, 

2004 2004

( | 0) ( | 0)

min , .

ij ij ij ij

i i

ij ij

i i

brand growth brand growth brand growth brand growth

brand brand

           

 

 
24

For example, if within a market growing brands add 30 stores while shrinking brands 

close 20 stores, we would measure the net churn among brands as 20 stores (growing 

brands replaced 20 of the stores closed by shrinking brands). If big-box grocery retailers 

operated 100 stores in that market in 2004, we would say that market churn for that 

market is 20%. 

We present the results from this calculation in a frequency histogram (Figure 5) 

separately for metro, large, and medium markets.32 Figure 5 shows that churn in relative 

market position of retail brands is substantial in medium, large, and metro markets. Half 

of metro markets, for example, experience churn of at least 11% between 2004 and 2009; 

that is, in these markets growing brands increase the number of stores they operate by at 

least 11% while shrinking brands contract their operations by at least the same amount. 

In medium sized cities churn is somewhat smaller, the median market experiences churn 

of about 8% and 25% of markets experience no churn. 

We conduct a similar calculation to measure changes in the corporate ownership 

of retail outlets. We calculate each firm’s (i’s) net growth (across all brands operated by 

the firm) in market j (firm growthij) as the difference in the number of stores it operated 

in 2009 and 2004 (where firmijx is the number of stores operated by firm i in market j in 

year x): 

2009 2004 . ij ij ij firm growth firm firm  

Within a market, j, we group firms into those that were shrinking (firm growthij <0) and 

growing (firm growthij >0) and then calculate the total number of stores that were added 

by growing firms or eliminated by firms that were shrinking. We then measure within 

market changes in relative size as the minimum of the proportional change in the number 

of stores either operated by growing or shrinking firms; that is, 

2004 2004

( | 0) ( | 0)

min , .

ij ij ij ij

i i

ij ij

i i

firm growth firm growth firm growth firm growth

firm firm

     

 

 

 

 

32 We have not presented results for small/city retail markets these markets tend to have very few total 

stores in operation (see Table 1). Changes in market configuration in these markets are rare and are 

typically the result of entry or exit. 
25

We present the results from this calculation as a frequency histogram (Figure 6) 

separately for metro, large, and medium markets. There is considerably more churn 

among the size of firms operating within markets than retail brands within markets. 

When measuring churn among retail brands no metro market experiences turnover of 

greater than 25% (see Figure 5). In contrast, when measuring churn at the firm level one 

metro market experienced churn of 50%. The median market experienced firm turnover 

of about 12%, 17%, and 19% in medium, large, and metro markets, respectively. This is 

compared to the retail brand churn of 8%, 12%, and 11%, for the median market in 

medium, large, and metro markets. 

V. Conclusion 

This paper measures market dynamics within the big-box grocery retailing 

industry in the U.S. during a recent six year period. Despite being a mature industry -- 

with roughly 31,000 outlets each year during our sample period-- we observe substantial 

changes in the stock of stores in operation. In particular, the fraction of retail outlets 

operated as supercenters and club stores has grown rapidly at the expense of traditional 

supermarkets. However, even traditional supermarket retailers continue to upgrade the 

stock of stores they operated as supermarkets. During our sample period supermarket 

retailers opened new outlets representing roughly 2% of the stores in operation each year. 

 Our findings have important implications for studies of market dynamics. While 

entry and exit by small firms was a common feature of big-box grocery retailing, 

collectively entry and exit were responsible for only a fraction of the change in the 

relative size of retail brands operated within a market. Further when entry occurs, outside 

of the smallest markets, entrants rarely quickly gain a substantial share of market 

revenue. However, the failure of entrants to rapidly expand does not imply that local 

retail markets are best viewed as static oligopolies. In fact, we see significant turnover in 

the number of stores operated by different retail brands in most medium and large city 

and metro markets during our sample period. For example, the median metro market saw 

growing brands collectively expand their operations by 11% at the expense of shrinking 

brands. Our findings suggest that competition in these markets is significant and largely 

driven by interactions between firms operating incumbent brands. 
26

Finally, we find that the retailers operating relatively new and differentiated 

products, clubs and supercenters retailers, are experiencing the greatest rate of growth 

(both as entrants and as incumbent retailers). This finding is consistent with Klepper and 

Thompson (2006) who predict that in mature markets entry (and presumably expansion) 

does not occur in existing submarkets (in our case traditional supermarkets) but rather in 

new submarkets (club stores and supercenters). 
27

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525-43 
Tables and Figures 

Table 1: Distribution of Store Size and Revenue of Conventional Supermarkets, Supercenters, and Clu

 Weekly Revenue ($ Thousands) Store Size (Thousands of Square F Percentile 

Retailer Type Mean 

Standard 

Deviation 10 25 50 75 90 Mean 

Standard 

Deviation 10 25 

Conventional Supermarkets:  Independent Store 102 67 50 70 90 125 175 13.5 8.7 5 8  Small Chain (2-100 Stores) 196 159 70 90 150 225 375 24.4 13.3 10 15  Large Chain (> 100 Stores) 289 136 150 200 275 350 475 32.3 9.4 21 26 Big Box Formats:  Supercenter 926 339 475 675 925 1,175 1,350 61.9 10.7 49 54  Club Store 1,086 463 625 775 975 1,300 1,675 66.0 14.3 46 52 

Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009. 

Table 2: Mean Number of Stores and Grocery Revenue Share by Market Type and Retailer Type

Retailer Type Mean Stores and Revenue Share Within a Market Type 

 Rural/Small City Medium City Large City Metro 

 Stores Share Stores Share Stores Share Stores Share Independent 1.20 28.5% 6.88 7.2% 32.96 5.9% 191.28 7.6% Small Chain (2-100 Stores) 1.04 26.0% 7.54 13.2% 29.30 11.3% 156.50 13.8% Large Chain (> 100 Stores) 0.88 20.8% 12.94 32.1% 99.35 41.8% 370.67 46.7% Supercenter 0.42 24.3% 3.72 36.5% 20.02 27.7% 32.81 15.1% Club 0.02 0.4% 1.19 11.0% 8.75 13.3% 36.33 16.7% Number of Markets in 2004 1,593 261 40 12 Share of U.S. Population 12.7% 25.0% 26.6% 35.7% 

Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009. 

Table 3: Total Number of Stores by Year and Retailer Type 

Retailer Type Year 

 2004 2005 2006 2007 2008 2009 

Independent Store 7,623 7,511 7,386 7,149 7,113 7,119 Small Chain (2-100 Stores) 6,626 6,581 6,491 6,802 6,815 6,688 Large Chain (> 100 Stores) 13,901 13,488 13,090 12,883 12,875 12,937 Supercenter 2,174 2,463 2,760 3,040 3,256 3,329 Club 1,032 1,065 1,117 1,152 1,184 1,201 Total Number of Stores 31,356 31,108 30,844 31,026 31,243 31,274 

Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009.
Store Characteristic Independent Supermarkets Chain Supermarkets Supercenters C

Continuing Stores 107 259 943 1

(72) (143) (318) (

Opening Stores 100 255 869 

(52) (150) (342) (

Closing Stores 94 183 473 

(49) (103) (288) (

Continuing Stores 14.2 29.9 61.6 6

(8.5) (11.1) (10.4) (1

Opening Stores 11.4 29.8 61.0 6

(8.2) (12.9) (11.4) (1

Closing Stores 13.0 28.7 53.4 6

(8.7) (11.3) (12.7) (1

Continuing Stores 4.25 5.28 5.49

(2.62) (3.12) (2.53)

Opening Stores 4.35 5.19 4.76

(1.92) (1.54) (2.56)

Closing Stores 4.29 4.11 2.58

(2.67) (1.63) (2.16)

Standard Deviations in parentheses.* The number of employees in club stores was not included in the data, so that we could not calculate revenue per employee.Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009.

Table 4: Comparison of Means of Store Characteristics of Opening, Closing, and Continuing Stores

Log of a Store's Total 

Weekly Revenue per 

Employee ($Thousands)

Log of Grocery Square 

Footage 

(Thousands)

Weekly Grocery Revenue 

($Thousands)
Store Characteristic VARIABLES Independent Supermarkets Chain Supermarkets Superc

Opening Stores -0.0551*** -0.0507*** -0.15

(0.0183) (0.0117) (0.01

Closing Stores -0.106*** -0.262*** -0.31

(0.0140) (0.0123) (0.04

Chain Fixed Effects n/a Yes YeRegion Type Controls Yes Yes YeObservations 9778 25560 34R-squared 0.062 0.641 0.4Opening Stores -0.280*** -0.0198* -0.044

(0.0299) (0.0116) (0.00

Closing Stores -0.164*** -0.0527*** -0.06

(0.0207) (0.00914) (0.03

Chain Fixed Effects n/a Yes YeRegion Type Controls Yes Yes YeObservations 9778 25560 34R-squared 0.036 0.558 0.2Opening Stores 0.0577 0.0144* -0.11

(0.0368) (0.00857) (0.01

Closing Stores 0.00426 -0.222*** -0.26

(0.0171) (0.0123) (0.1

Chain Fixed Effects n/a Yes YeRegion Type Controls Yes Yes YeObservations 9778 25560 34R-squared 0.007 0.347 0.3

Standard errors calculated assuming clustering by geographic market.* The number of employees in club stores was not included in the data, so that we could not calculate revenue per employee.Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009.

Log of Weekly Grocery 

Revenue

Log of Grocery Square Footage

Log of a Store's Total Weekly 

Revenue per Employee 

Table 5: Regression of Store Characteristics on Indicators for Opening and Closing Stores
Table 6: Number of Entry Events, Stores Opened as a Result of Entry, and Average Number of Entry 

Events by Market and Retailer Type 

Firm Type Total US Average Number of Events Within a Market Type 

 Entry Events 

Stores Involved 

in Entry 

Rural/ 

Small City Medium City Large City Metro 

 Panel A: All Banner Entries (Brand Entry) 

Independent 1,605 1,605 0.15 1.45 7.70 57.00 

Small Chain 383 492 0.10 0.51 1.08 3.58 

Large Chain 219 473 0.07 0.25 0.68 0.83 

Supercenter 274 289 0.14 0.15 0.13 0.25 

Club 48 50 0.01 0.10 0.15 0.08 

Total Count 2,529 2,909 

 Panel B: Banner Entry through Firm Entry (Firm Entry) 

Independent 1,605 1,605 0.15 1.45 7.70 57.00 

Small Chain 245 288 0.06 0.33 0.73 2.50 

Large Chain 102 172 0.04 0.11 0.20 0.42 

Supercenter 247 256 0.14 0.09 0.05 0.08 

Club 28 30 0.00 0.06 0.15 0.08 

Total Count 2,227 2,351 

 Panel C: Incumbent Firm Introduces New Banner (Banner Entry) 

Small Chain 138 204 0.04 0.18 0.35 1.08 

Large Chain 117 301 0.04 0.14 0.48 0.42 

Supercenter 27 33 0.00 0.06 0.08 0.17 

Club 20 20 0.01 0.05 0.00 0.00 

Total Count 302 558 

Number of Markets in 2004 1,593 261 40 12 

Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009. 

 
Table 7: Number of Exit Events, Stores Closed as a Result of Exit, and Average Number of Exit Events 

by Market and Retailer Type 

Firm Type Total US Average Number of Events Within a Market Type 

 Exit Events 

Stores Involved 

in Exit 

Rural/ 

Small City Medium City Large City Metro 

 Panel A: All Banner Exits (Brand Exit) 

Independent 1,980 1,980 0.27 1.84 10.23 54.92 

Small Chain 547 703 0.19 0.59 1.38 3.25 

Large Chain 408 1,117 0.14 0.49 0.95 1.75 

Supercenter 10 11 0.00 0.01 0.13 0.08 

Club 1 1 0.00 0.00 0.03 0.00 

Total Count 2,946 3,812 

 Panel B: Banner Exit through Firm Exit (Firm Exit) 

Independent 1,980 1,980 0.27 1.84 10.23 54.92 

Small Chain 360 463 0.14 0.37 0.63 1.58 

Large Chain 292 880 0.11 0.36 0.53 0.75 

Supercenter 10 11 0.00 0.01 0.13 0.08 

Club 1 1 0.00 0.00 0.03 0.00 

Total Count 2,643 3,335 

 Panel C: Continuing Firm Exits Banner (Banner Exit) 

Small Chain 187 240 0.05 0.23 0.75 1.67 

Large Chain 116 237 0.03 0.13 0.43 1.00 

Supercenter 0 0 0.00 0.00 0.00 0.00 

Club 0 0 0.00 0.00 0.00 0.00 

Total Count 303 477 

Number of Markets in 2004 1,593 261 40 12 

Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009. 
Table 8: Total and Mean Number of Stores Added as a Result of 

Within Market Expansion of Incumbent Brands by Retailer and Market Type

Retailer Type Mean Number of Stores Added in Market Type Total Stores Added 

 

Rural/ 

Small City Medium City Large City Metro 

Net Growth in 

Expansion 

Small Chain (2-100 Stores) 0.04 0.88 5.30 26.75 822 

Large Chain (> 100 Stores) 0.02 1.07 11.33 24.25 1,060 

Supercenter 0.01 1.20 8.73 17.17 888 

Club 0.00 0.08 1.40 4.50 130 

Number of Markets in 2004 1,593 261 40 12 2,900 

Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009. 

Table 9: Total and Mean Number of Stores Added as a Result of Banner Entry by Retailer and Market Type

Retailer Type Mean Number of Stores Added in Market Type Total Stores Added 

 

Rural/ 

Small City Medium City Large City Metro Entry Events 

Small Chain (2-100 Stores) 0.11 0.67 1.38 6.58 492 

Large Chain (> 100 Stores) 0.09 0.52 1.93 10.00 473 

Supercenter 0.14 0.18 0.18 0.42 289 

Club 0.01 0.10 0.20 0.08 50 

Number of Markets in 2004 1,593 261 40 12 1,304 

Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009. 

Table 10: Total Number of Stores Closed as a Result of 

Within Market Contraction of Incumbent Brands by Retailer and Market Type

Retailer Type Mean Number of Stores Closed in Market Type Total Stores Closed 

 

Rural/ 

Small City Medium City Large City Metro 

Net Shrinkage in 

Contraction 

Small Chain (2-100 Stores) 0.06 0.96 4.30 23.50 795 

Large Chain (> 100 Stores) 0.03 1.17 10.30 38.50 1,227 

Supercenter 0.00 0.00 0.18 0.08 9 

Club 0.00 0.00 0.10 0.42 10 

Number of Markets in 2004 1,593 261 40 12 2,041 

Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009. 

Table 11: Total and Mean Number of Stores Closed as a Result of Banner Exit by Retailer and Market Type

Retailer Type Mean Number of Stores Closed in Market Type Total Stores Closed 

 

Rural/ 

Small City Medium City Large City Metro Exit Events 

Small Chain (2-100 Stores) 0.20 0.89 2.28 5.50 703 

Large Chain (> 100 Stores) 0.16 1.13 8.10 20.33 1,117 

Supercenter 0.00 0.01 0.15 0.08 11 

Club 0.00 0.00 0.03 0.00 1 

Number of Markets in 2004 1,593 261 40 12 1,832 

Source: Author calculations using grocery retail data provided by AC Nielson’s Trade Dimensions database covering 2004 – October 2009. 
Figures 

Figure 1: Estimated Share of Grocery Revenue by Retailer Type 

Figure 2: Ratio of Store Openings and Closings to Total Stores in Operation by Retailer Type 
Figure 3: Distribution of Revenue Share of Entering Firms in Second Year Following Entry by 

Retailer and Market Type 
Figure 4: Distribution of Revenue Share of Entering Brands Operated by Incumbent Firms in 

Second Year Following Entry by Retailer and Market Type
Figure 5: Frequency Histogram of Banner Churn by Market Type 

Figure 6: Frequency Histogram of Churn in Brand Ownership by Market Type