Just-in-time consumption: Does the `pint of milk test’ hold water?

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Growth of international trade indicates society has not entered an age of “dematerialization” as has been debated. [Herman et al., 1990,Wernick et al., 1996,Heiskanen and Jalas, 2000] While individual objects may be getting smaller, consumers have been steadily acquiring more objects. This paper explores where that acquisition occurs.

Just-in-time production revolutionized manufacturing, enabling both a reduction in inventories as supplies arrive only shortly before needed, and an improvement in quality as poorly made inputs are no longer stored for long periods of time, but can be quickly identified and feedback provided to the supplier. The widespread adoption of the just-in-time process is itself the product of the logistics revolution, information and communications technologies, containerization in shipping, and the interstate highway system. It has seen a concomitant change in the retail sector, which has brought about fewer and larger stores at a greater distance from the end consumer.

The notion of just-in-time consumption has not received the same attention as just-in-time production. The phrase itself, though seemingly a natural mirror to the more widely used “just-in-time production” only generates 821 hits in Google, of which only a few are on-point, in comparison to over 153,000 for “just-in-time production”. 2

Yet many goods and services are already consumed in a just-in-time manner. Most notable is energy, which is delivered on-demand to users, who no longer store coal at home for the furnace, but instead buy natural gas or electricity as needed. (The slowly vanishing home heating oil remains an exception). Other services that are provided on-demand or just-in-time include water and sewer, communications (both telephony and television). What is in common about these disparate technologies is their network nature, the large infrastructure required to enable using the flows on-demand. While sewer is a continuous service for most people (those who do not have septic tanks), garbage is typically only collected periodically (e.g. once a week), and recycling less so (e.g. fortnightly).

Other goods once saw regular to-the-house delivery, especially in suburban areas. Foxell [2005] writes of goods and services found in Metro-land, the idyllic north London suburbs built by the Metropolitan railway in the early twentieth century “This service economy is illustrated by the variety of tradesmen that called at our home: the milkman twice a day, with a horse-drawn cart; the baker once a day, with a large upright barrow on two wheels, the handles of which lifted him off the ground when going down hill; the postman thrice; the butcherÕs boy by bicycle twice a week; and the grocer twice a week. Others like the coalman or the Gas, Light & Coke Co. in their steam-powered Sentinel lorry also made regular deliveries. Over a longer period, visits could be expected from the men from the Prudential [insurance], Hoover [vacuum cleaners], Singer [sewing machines] and the like ∆ all using a service call to take the opportunity to sell new products. There was something reassuring about seeing such familiar faces and catching up with the latest gossip. In addition there were the itinerant callers such as Walls Ice Cream man on his tricycle as well as the French onion sellers, gypsies with pegs and posies, rag and bone men, tinkers [metalsmiths] and the knife-sharpeners with their pedal-driving grinding wheels.”

Today, the vast majority of those goods are not acquired at home but in stores or online. Delivery services have replaced salesmen, as the two functions (delivery and sales) are now distinct and specialized. Today’s visitors might be the post office, FedEx or UPS, and the pizza delivery boy.

Just-in-time does not require delivery to the residence, it can involve ubiquity in the placement of stores, so that they are near the end consumer. Traditionally the retail store was just that, a place where a community could store goods, and individuals could take or buy them as needed.

Many planners would like to make the ability to acquire goods just-in-time without the use of a vehicle a normative planning standard. For instance, a report, Beyond 2010: A Holistic Approach to Road Safety in Great Britain calls for the “pint of milk test”, for all new developments, whereby a resident can get to a shop to buy a pint of milk in 10 minutes or less without getting in their car [Parliamentary Advisory Council on Transport Safety, 2007]. The idea of 10 minutes comes from people’s willingness to walk, people are less willing to walk longer distances than shorter, and 10 minutes (or one-half mile (0.8 km)) seems to be a threshold over which walking tolerance seems to drop. This distance was derived from several empirical studies, including Pushkarev and Zupan [n.d.], who showed the median walk by travelers accessing the New York subway was 0.35 mi (0.57 km), while the median walk to access commuter rail stations in suburban New Jersey was 0.5 to 0.6 mi (0.8 – 1.0 km). Results from the 1983/84 National Personal Transportation Survey reported by Unterman [1990] found shorter distances: 70 percent of Americans will walk 500 feet (0.15 km) for normal daily trips, 40 percent walk 1,000 feet (0.31 km), and only 10 percent walk a half-mile (0.8 km).

The pint of milk refers to a standard quantity of a highly perishable and frequently consumed good. The objective of avoiding car use is obvious for a group advocating road safety. The pint of milk test has received some currency in England, being noted by several studies in recent years [Bennett and Morris, 2006,Marsh, 2004]. This is a particular issue in a crowded city like London, where auto ownership is lower than suburban areas, roads are more crowded, and parking more difficult even for those with a car.

The trends in retailing have been clear in the United States for a long time. Stores are getting larger and gaining larger market areas [Yim, 1990]. Small stores serving local areas have been losing market share to larger stores which bring with them economies of scale. Efforts to reverse this trend have met with resistance from retailers, consumers, and neighbors [Nelson and Niles, 1999].

Illustrating this trend, the Food Marketing Institute reports in 2006 there were 34,019 supermarkets (with $2 million in sales or more, noting the median annual sales for a supermarket was $17 million, and average size was 48,705 sq. ft. ( m2)). The average number of trips per week consumers make to the supermarket was 1.9.
3

In 1930, The Great Atlantic and Pacific Tea Company, at the time the leading US supermarket, alone had 16,000 stores with a combined revenue of $1 billion (or per store revenue of $62,500 in 1930 dollars, estimated to be $754,000 today) 4 [The Rise and Decline of the Great Atlantic and Pacific Tea company, n.d.]

Handy [1993] claims “the automobile instigated a collapse of the retail hierarchy by encouraging the growth of community and regional centers at the expense of local shops and the central business district. The result has been a cycle of dependence, in which suburban communities are designed for the automobile leaving residents little choice but to drive.”

As with stores, houses too are getting larger. New suburban homes have more space to store goods in-house. While urban residents export storage to common stores, suburban residents more likely to have second freezers, have more space to store stuff.

While the number of freezers per household in the United States is declining as second freezers are being retired and not replaced, the number of refrigerators is increasing slightly, due to households obtaining second refrigerators. [Wenzel et al., 1997]. While no immediate inference can be made about this, other trends are also at work. Total refrigerated and frozen space has not been computed, though the average size of a house’s primary refrigerator or freezer is likely increasing. Food may last longer in refrigerators than it used to due to the addition of preservatives (though the trend of increased consumption of organic foods may reverse this). Further globalization may mean that fewer goods are seasonal and need to be accumulated prior to their being out-of-season.

Persson and Bratt [2001] note that e-shopping may induce the installation of a second set of fridge/freezers per household to receive delivered goods. This additional electricity consumption has environmental consequences; already, there are 2.2 refrigerators and freezers per household in New Zealand (Roke, 2006) cited in [New Zealand Ministry for the Environment, n.d.].

If urban residents do undertake more just-in-time consumption than suburbanites both because of the higher storage costs associated with smaller houses, and the greater opportunity afforded by more stores nearby, we would expect to see this show up in the travel behavior data that is collected by urban regions.


Minneapolis St. Paul Remainder of Hennepin County
Year Structure Built 1926 1929 1970
Sq. Ft. 1773 1826 2152
Sq. Ft. per Person 822 755 810
Households with No Cars 5900 2800 2500

Table 1 illustrates some of the differences between the City of Minneapolis, suburban Hennepin County (Hennepin excluding the City of Minneapolis), and the City of St. Paul in neighboring Ramsey County. Residents of Minneapolis live in older houses (average year built of 1926 vs. 1970 in the suburbs) with 1773 square feet vs. 2152 in the suburbs. However because of the lower household size, city residents actually have slightly more area per person. Further Minneapolis residents are more likely to be carless.

According to the 2000/2001 Twin Cities Travel Behavior Inventory among residents of the City of Minneapolis, 12.8 percent of daily trips were for shopping 5 while for Hennepin County excluding the City of Minneapolis the number was 12.2 percent 6. Thus Minneapolitans devote 5 percent more of their trips to shopping than suburban Hennepin County residents.

Minneapolitans also make slightly more trips than their suburban brethren, 3.81 per day vs. 3.70 for suburban Hennepin. Unfortunately, it is difficult to ascertain whether total trip making is rising because of differences in survey methodology over time, though one expects it is. 7. Given the small differences and their temporal instability, it probably is unreasonable to make much of them

The evidence weakly supports the hypothesis that city residents who have somewhat higher accessibility to neighborhood stores and somewhat reduced storage space at home shop more frequently.

Broadly, there are two types of places, those that satisfy the pint of milk test, and those that don’t. Similarly, there are two kinds of people, those who care about the pint of milk test and those who don’t. The problem comes from the mismatch of those who care but live in places that are unsatisfactory. (Those who don’t care but live in places passing the test are probably okay). If self-selection is at work, these cells are not randomly distributed, but people who want to live in particular environments do so. People who prefer milk-accessible areas bid up prices in those areas, while those who are indifferent (or perhaps lactose-intolerant) move out. However, if preferences change faster than spatial structure, there may be a mismatch. Policy that excludes mixture of residential and commercial development may also foster a mismatch.

Evidence from the Twin Cities bears on the issue (Figures 1 to 4). According to the American Housing Survey [US Census Bureau, n.d.], over 80 percent of residents in the City of Minneapolis report satisfactory neighborhood shopping within a mile of home, compared with 70 percent of those in suburban Hennepin County (Figure 1). Despite that positive assessment of shopping, suburban Hennepin residents have a better opinion of their own neighborhood than those in the City of Minneapolis (Figure 2). The problems these urbanites report in greater numbers than their suburban counterparts are noise and traffic, crime, and odors (Figure 3).

When people move, they are doing so to places they believe are better, but for all residents it is the home that is better than previous much more so than the neighborhood, and in Minneapolis, only a third rate their current neighborhood as better than their previous (in contrast to half of suburban residents) (Figure 4).

To the extent neighborhood shopping enabling just-in-time consumption of the pint of milk is important to people, cities fare better than their suburbs, but if the cost of that neighborhood shopping is other urban ills, people will make the trade-off, sacrificing access to retail to have access to quite and congestion free, safe, and pleasantly smelling suburban environments.

Whether this is a social good is another question entirely, and depends on relative efficiency of urban goods delivery services, energy efficiency of in-store displays vs. at-home refrigeration units, and numerous other questions.

References

Bennett, J.  Morris, J. 2006 ,
Gateway people, Technical report, Institute for Public Policy Research.

Foxell, C. 2005 , Rails to
Metro-Land.
, Clive Foxell, Chesham, Bucks, England.

Handy, S. 1993 , “A Cycle of Dependence:
Automobiles, Accessibility, and the Evolution of the Transportation and
Retail Hierarchies”, Berkeley Planning Journal , Vol. 8, pp. 21-43.

Heiskanen, E.  Jalas, M. 2000 ,
Dematerialization Through Services: A Review and Evaluation of the
Debate
, Ministry of Environment: Edita, jakaja.

Herman, R., Ardekani, S.  Ausubel, J.
1990 , “Dematerialization”, Technological
Forecasting and Social Change
, Vol. 38(3), pp. 333-347.

Marsh, G. 2004 , “Tesco piles ‘em high:
Flats above supermarkets are a good buy”, The Times , Vol. June 18,
2004.

Nelson, D.  Niles, J. 1999 ,
“Market Dynamics and Nonwork Travel Patterns; Obstacles to Transit-Oriented
Development?”, Transportation Research Record , Vol. 1669,
Transportation Research Board of the National Academies, pp. 13-21.

New Zealand Ministry for the Environment
n.d. , Technical report.

Parliamentary Advisory Council on Transport Safety
2007 , Beyond 2010: A Holistic Approach to Road Safety in
Great Britain, Technical report, Parliamentary Advisory Council on Transport
Safety.
Parliamentary Advisory Council for Transport Safety

http://news.bbc.co.uk/1/hi/uk/7046200.stm.

Persson, A.  Bratt, M. 2001 ,
“Future CO 2 savings from on-line shopping jeopardised by bad planning”,
Proceedings of the 2001 ECEEE Summer Study ÔFurther than Ever from
Kyoto
.

Pushkarev, B.  Zupan, J. n.d. ,
“Where Transit Works: Urban Densities for Public Transportation”,
Urban Transportation: Perspectives and Prospects
, pp. 341-344.

The Rise and Decline of the Great Atlantic and Pacific Tea company
n.d. .

Unterman, D. 1990 , `Accommodating the
Pedestrian: Adapting Towns and Neighborhoods for Walking and Bicycling.
Personal Travel in the US, Vol. II: A Report of the Findings from 1983-1984
NPTS, Source Control Programs’.

US Census Bureau n.d. , American Housing
Survey for the Minneapolis St. Paul Metropolitan Area, Technical report, US
Census Bureau.
1998AHS: Minneapolis h170-98-9.

Wenzel, T., Koomey, J., Rosenquist, G., Sanchez, M.  Hanford, J.
1997 , “Energy Data Sourcebook for the US
Residential Sector”, Lawrence Berkeley National Laboratory, Report ,
Vol. 40297.

Wernick, I., Herman, R., Govind, S.  Ausubel, J.
1996 , “Materialization and Dematerialization: Measures
and Trends.”, Daedalus , Vol. 125(3), American Academy of Arts and
Sciences.

Yim, Y. 1990 , The Relationship Between
Transportation Services and Urban Activities: The Food Retail Distribution
Case, PhD thesis, University of California, Institute of Transportation
Studies.

Figure 1 Satisfactory Shopping
Figure 2 Opinion of Neighborhood
Figure 3 Urban Problems
Figure 4 Comparison


Footnotes:

1David Levinson is RP Braun-CTS Chair of Transportation Engineering; Director of Network, Economics, and Urban Systems Research Group; University of Minnesota, Department of Civil Engineering, 500 Pillsbury Drive SE, Minneapolis, MN 55455 USA, Email: dlevinson@umn.edu, web: http://nexus.umn.edu

2By just-in-time consumption, I mean acquisition of a good by the end consumer shortly before its use, rather than being acquired and stored for future use.

3http://www.fmi.org/facts_figs/superfact.htm (now offline and found in Google cache; Sources: U.S. Department of Labor, U.S. Department of Agriculture, Progressive Grocer magazine, U.S. Census Bureau, and Food Marketing Institute

4Conversion factor from Samuel H. Williamson, “Five Ways to Compute the Relative Value of a U.S. Dollar Amount, 1790 – 2006,” http://MeasuringWorth.Com, 2007. Alternative conversions include:

  • $754,491.02 using the Consumer Price Index
  • $631,644.95 using the GDP deflator
  • $2,355,247.64 using the unskilled wage
  • $3,715,127.08 using the nominal GDP per capita
  • $9,042,420.50 using the relative share of GDP

52,223 shopping trips, 17,353 total trips (4555 people)

6828 shopping trips, 6785 total trips) (1830 people)

7Calculations using the 1990 TBI indicates that Minneapolitans reported on average 4.70 trips per person in 1990, while suburban Hennepin residents reported 4.85 per person


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