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advance the interests of
consumers in Queensland
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Australia
8 May 2017
CONSUMER USES OF UNIT PRICES FOR VALUE
COMPARISONS IN AUSTRALIAN SUPERMARKETS
EXECUTIVE SUMMARY
104 Australian consumers with a special interest in consumer issues provided information on-line
about their use of unit pricing (price per unit of measure) when shopping for food and grocery
products in supermarkets. Respondents indicated how often they use unit pricing for five types of
values comparisons provided to them. Each type was reportedly used to some degree by a very high
proportion (100% to 95%) and a high proportion reportedly used it frequently (89% to 70%).
The uses with the highest percentages for frequent use were to compare:
 the same brand’s pack sizes (89%),
 regular and special offer prices (88%),
 different brands and pack sizes (84%).
The uses with the lowest percentages for frequent use were to compare:
 products packaged and loose from bulk (78%),
 simple and complex packaging (70%).
BACK GROUND
A high proportion of adult Australian shoppers say they use unit pricing (price per unit of measure)
when shopping for food and grocery products in supermarkets.
For example in a 2011 national on-line survey1, 80% of around 1000 adult shoppers at Coles and
Woolworths supermarkets said they were using unit prices, and 72% of users said they found unit
prices very helpful.
However, information is not publicly available on why and how Australian consumers use unit
prices2. This is a major knowledge gap because such information is very relevant to unit pricing
policies and practices.
Therefore, an exploratory investigation of this issue was undertaken by seeking information from
members of a national on-line forum for consumers with a special interest in consumer issues.
1
Choice and Qld Consumers Assoc, Report of Survey of Consumers on Grocery Unit Pricing at Coles/Bilo and
Woolworths /Safeway Supermarkets, Nov. 2011. Available at http://consumersfederation.org.au/wpcontent/uploads/2011/12/UP_Survey_Report_-_FINAL1.pdf
2
And overseas the only recent work on detailed consumer usage was in the USA by Manning K, Sprott D, and
Miyazaki A, (2003): “Unit Pricing Usage and Knowledge”, Journal of Business Research, 56(5), pp 367-77,who
identified 8 comparison usage categories for unit prices of products in constant measure packages. However,
they analysed consumer “unit price usage knowledge” not reported usage.
1
METHOD
Members of the Choice Community, an on-line forum for members and supporters of Choice
(Australian Consumers Association) a national membership-based consumer organisation, were
invited to provide information about whether, and if so how frequently, they use unit pricing to
compare values in supermarkets.
In Australia, large supermarkets are required provide unit prices for products sold in three main
ways: loose from bulk, in random measure pre-packs, and in constant measure pre-packs ( see
Appendix 1). However, provision of unit pricing (in addition to the selling price) has only been
required for products in constant measure pre-packs since 2009 and public discussion of the topic
normally is about this type of unit pricing. Also, these packages likely represent a high proportion of
all the products bought by many supermarket shoppers.
The investigation wished to obtain information about consumer use of the three types of unit pricing
to compare the value of various products and offers. Therefore, to ensure that respondents were
aware that information was sought about all three types of unit pricing and that the focus was on
value comparisons3, the following information preceded the questions:
“Large supermarkets provide unit prices for products sold:
• Loose from bulk (for example fruit and vegetables, meat, fish, and cheese - usually priced per kg),
• In variable weight packs (for example transparent packs of meat, fish and cheese– the unit price in
$/kg is on the label)
• In constant measure packs (for example cans of vegetables, cartons of breakfast cereal, packets of
frozen fish, and bags of fresh fruit and vegetables – the unit price is on the shelf label.,
Therefore, shoppers can now use unit prices for several types of value comparisons in large
supermarkets.”
Following discussions with other consumers, it was decided to seek information about the use of
unit prices for the following five types of value comparisons:
TYPE 1. Products sold packaged and loose from bulk, for example cheese/cooked meats/nuts/fruit
and vegetables.
TYPE 2. Different pack sizes of the same brand of a product, for example one brand of breakfast
cereal.
TYPE 3. Different brands and pack sizes of a product, for example different pasta brands and pack
sizes.
TYPE 4. Regular prices and temporary special offers, for example discounts/multi-buys/"free" extra
quantity.
TYPE 5. Products sold in simple and complex packaging, for example drink powder loose in a pack or
in a pack containing sachets.
Respondents were asked to indicate how often they used unit prices for each type of comparison
and were given the following choices: Frequently/sometimes/rarely/never4.
3
Other possible uses include quality assessment explored in Yan D, Sengupta J, and Wyer R, (2014): Package
Size and Perceived Quality: The Intervening Role of Unit Price Perceptions. Journal of Consumer Psychology,
Vol.24, No.1, pp 74-84.
4
How often respondents use unit prices may NOT accurately (except perhaps for “never”) reflect the
usefulness of, or benefits derived from, unit pricing. For example, some consumers may have used unit prices
intensively in the past to determine what to buy on an on-going basis and now may only compare unit prices
infrequently, especially if using a supermarket with an everyday low pricing (EDLP) policy.
2
RESULTS
There were up to 104 responses to each question and the results are summarised in Table 1 below.
Table 1
TYPE OF USE
Same brand pack sizes
Regular and special offer prices
Different brands and pack sizes
Packaged and loose from bulk
Simple and complex packaging
Frequently
89
88
85
77
70
% responses by frequency of
use
Sometimes Rarely
Never
6
4
1
10
2
0
9
4
2
14
6
3
17
9
5
(n=104)
(n=104)
(n=104)
(n=102)
(n=102)
Given that respondents were likely to be well above average in knowledge of and interest in
consumer issues and also in interest in comparing value for money, as expected, most respondents
said they used each type of use to some degree. For example the percentage that never used unit
prices for a use type ranged from only 5% to zero. Also, a very high percentage of respondents said
they used unit prices frequently for all of the uses - the range was only from 89% to 70%.
The three uses made most frequently were comparisons of:
the same brand’s pack sizes (89%), regular and special offer prices (88%), and different brands and
pack sizes (84%). However, there were no statistically significant differences between these uses at
the 5% probability level.
The two uses with the lowest percentages for frequent use were to compare:
products packaged and loose from bulk (78%) and simple and complex packaging (70%). However,
there was no statistically significant difference between these uses at the 5% probability level.
The 70% result for frequently used for comparing simple and complex packaging was statistically
significant from the 3 largest frequently used percentages, and the 78% frequently use for
comparing packaged with loose from bulk was statistically significant from the largest frequently
used percentage (same brand’s pack sizes 89%).
The statistical test results are shown in Appendix 2.
DISCUSSION
Although this was an exploratory exercise and with consumers likely to be above average users of
unit pricing, the results are still very relevant to policy/provision issues and to future research on this
topic because:
 Very high percentages of respondents said they used unit pricing overall and frequently for
each of the five types of value comparisons investigated. (These usage percentages are
consistent with estimates of overall level of self-reported use obtained by other Australian
studies.)
 Many respondents used unit prices to compare values not only between different package
sizes within and between brands but also between products sold loose from bulk (where the
selling price is the unit price) and when sold in pre-packages (where the unit price is
provided in addition to the selling price).
 Many respondents used unit prices to compare regular and special offer prices.
 As expected, fewer respondents used unit pricing to compare the value of products in simple
or complex packages, however the overall use was still very high at 95% and 70% said they
did this frequently.
3
The high level of use to compare products sold loose from bulk and in pre-packages particularly
highlights the need for uniformity, or the highest possible level of consistency, in the measurement
units used to unit price products sold loose from bulk (regulated by Trade Measurement laws) and in
pre-packages (regulated by Trade Measurement and Unit Pricing laws).
More generally, the results confirm that many consumers use unit pricing and this highlights the
need for effective consumer focused unit pricing to be required by legislation and be provided by
retailers, including display5 of unit prices and choice of measurement units used for unit pricing.
LIMITATIONS AND IMPLICATIONS FOR FURTHER RESEARCH
The main limitations of this exploratory study were:
 The atypical population surveyed and the non-random selection of respondents. (Further
research should be with randomly selected consumers from the general population.)
 Only some of the possible uses of unit pricing for value comparisons were investigated.
(Other possible value comparisons for future investigation include: only between products
sold loose from bulk, only between products in random measure pre-packages, between
products loose from bulk and in random measure pre-packages, and between retailers).
 Only aggregates data could be collected. (Future studies should obtain data on individual
responses.)
 Self-reporting of usage. (Other data collection methods may be better and possible.)
Unit price usage for value comparisons may also vary between different types of products, for
example food and non-food products, and between product perceptions and prices levels, for
example luxury and non-luxury products and high and low priced products. Also, as investigated by
some recent research, unit pricing may be used for other purposes, such as to indicate quality.
Therefore, future studies should consider also investigating these usages.
5
In the 2011 Choice and QCA survey (op.cit.) 67% of all respondents said that unit prices would be more
helpful if either more prominent or more legible.
4
APPENDIX 1: EXAMPLES OF UNIT PRICING OF PRODUCTS SOLD
LOOSE FROM BULK AND IN RANDOM AND CONSTANT MEASURE
PRE-PACKAGES
Loose apples sold per kg (UP= $3 per kg)_
Chicken in random measure pre-package (UP= $18.29 per kg)
Margarine in constant measure pre-package (UP = $1.07 per 100g)
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APPENDIX 2: STATISTICAL SIGNIFICANCES
(n=102-104)
Statistical significance of differences between
proportions
% who use UP frequently
TYPE OF USE
Packaged and loose from bulk
Same brand pack sizes
Different brands pack sizes
Regular and special offer prices
Simple and complex packaging
Packaged
and loose
from bulk
77%
Same
brand
pack sizes
89%
Different
brands pack
sizes
84%
Regular and
special offer
prices
88%
*
ns
ns
ns
ns
ns
***
ns
*
**
77%
89%
84%
88%
70%
% who use UP frequently and
sometimes
(n=102-104)
Statistical significance of differences between
proportions
TYPE OF USE
Packaged and loose from bulk
Same brand pack sizes
Different brands pack sizes
Regular and special offer prices
Simple and complex packaging
Packaged
and loose
from bulk
91%
Same
brand
pack sizes
95%
Different
brands pack
sizes
96%
Regular and
special offer
prices
98%
ns
ns
*
ns
ns
ns
*
ns
*
**
91%
95%
96%
98%
87%
ns =
P > 0.05
*=
P ≤ 0.05
** =
P ≤ 0.01
*** =
P ≤ 0.001
6