Economic 

Research

Report

Number 71

February 2009

United States 

Department 

of Agriculture

Economic 

Research 

Service

Hiroshi Mori, Dennis Clason, Kimiko Ishibashi, 

William D. Gorman, and John Dyck

Declining Orange Consumption 

in Japan

Generational Changes or Something Else?
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Declining orange consumption in Japan : generational changes 

or something else?

 (Economic research report (United States. Dept. of Agriculture. 

Economic Research Service); no. 71)

 1. Orange industry—Japan.

 2. Oranges—Social aspects—Japan. 

 3. Food consumption forecasting—Japan.

 I. Mori, Hiroshi. 

 II. United States. Dept. of Agriculture. Economic Research 

Service.

 III. Title.

HD9259.O8

Photo Credit: Shutterstock
United States

Department

of Agriculture

www.ers.usda.gov

A Report from the Economic Research Service

Abstract

Japan is a leading market for U.S. oranges. Since 1995, orange consumption in Japan has 

declined. This report summarizes an analysis of household survey data to assess various 

factors that may be related to the decline. Consumption of oranges in Japan differs markedly across generations, with younger generations (cohorts) eating fewer oranges than 

older generations. However, within generations, as individuals in Japan grow older, they 

eat more oranges. On balance, the effects on consumption associated with aging and birth 

cohort membership are mostly offsetting. Orange prices affect consumption levels, but 

household income does not. Even after the analysis accounts for price and demographic 

variables, a strong downward trend is evident in orange consumption in Japan. Results 

suggest that orange consumption could decline even more in the future.

Keywords: Japan, oranges, consumption, age/period/cohort analysis

Acknowledgments

The authors gratefully acknowledge the econometric guidance by Yoshiharu Saegusa 

of Tokyo Metropolitan University and the comments and suggestions of Bill Coyle, 

Barry Krissoff, Mary Anne Normile, and Susan Pollack of USDA’s Economic Research 

Service (ERS); Kenzo Ito and Jess Paulson of USDA’s Foreign Agricultural Service; 

Yang Yang of the University of Chicago; Mechel Paggi of Fresno State University; and 

an anonymous reviewer. Excellent support was provided by the editor, John Weber, and 

the designer, Wynnice Pointer-Napper, both of USDA, ERS.

Hiroshi Mori, Dennis Clason, Kimiko Ishibashi, 

William D. Gorman, and John Dyck*

Declining Orange Consumption 

in Japan

Generational Changes or Something Else?

Economic

Research

Report

Number 71

February 2009

*Mori is at Senshu University, Japan; Clason and Gorman are at New Mexico State University, Las Cruces; 

Ishibashi is at the National Center for Agricultural Research, Tsukuba, Japan; and Dyck is at the U.S. 

Department of Agriculture, Economic Research Service.
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Contents

Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Household Purchases of Oranges by Age of Household Head. . . . . . . . . 5

Deriving Individual Consumption From Household Data. . . . . . . . . . . . 6

Decomposing Individual Consumption by Age From 

 1987 to 2006 Into Age, Cohort, and Period Effects . . . . . . . . . . . . . . . . 9

Discussion of Age, Period, and Cohort Effects . . . . . . . . . . . . . . . . . . . . 11

Economic Analysis of Period Effects on Orange Consumption—

 Are Oranges Normal Goods in Japan?. . . . . . . . . . . . . . . . . . . . . . . . . 14

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Recommended citation format for this publication:

Mori, Hiroshi, Dennis Clason, Kimiko Ishibashi, William D. 

Gorman, and John Dyck. Declining Orange Consumption in 

Japan: Generational Changes or Something Else? ERR-71, U.S. 

Dept. of Agri., Econ. Res. Serv. February 2009.
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Summary

Japan, a leading market for U.S. oranges, has registered declining consumption of oranges, and fresh fruits in general, in recent years. At the same time, 

Japan’s economy has seen little growth and its demographic changes have 

been profound as its elderly population has increased rapidly as a share of the 

country’s total population. The effects of aging and of generational change 

on food consumption appear to be major factors affecting orange consumption in Japan.

What Is the Issue?

Since about 1995, orange consumption (in aggregate and per person) has 

fallen in Japan. One theory attributes that decline to the aging of the population and the fact that younger Japanese eat fewer fresh oranges than older 

Japanese. Orange prices and income levels are also cited as factors that may 

be contributing to the dropoff in orange consumption over time. Suppliers to 

Japan’s orange market, largely U.S. growers, may benefi t from information 

on factors triggering the decline as they plan future market strategies in Japan 

and in such countries as South Korea, which is also characterized by an aging 

population.

What Did the Study Find?

As individuals in Japan grow older, they eat more oranges; however, older 

generations of Japanese are being steadily replaced by younger generations 

who, overall, eat fewer oranges. On balance, the effects on consumption 

associated with aging and birth cohort membership are mostly offsetting. 

Prices affect orange consumption in Japan, but household income does not. 

Even after the analysis accounted for price and demographic variables, a 

strong downward trend was evident in Japanese orange consumption. 

Specifi c fi ndings include the following:

• Studies show that as Japanese age, they eat more oranges. Thus, today’s 

Japanese youth are likely to increase their orange consumption as they 

grow older. The aging of Japan’s population therefore has a positive 

effect on orange consumption. 

• This analysis estimates, however, that, even in old age, today’s younger 

Japanese will not match the level of orange consumption of today’s 

elderly Japanese. The generational replacement of older birth cohorts by 

younger birth cohorts therefore has a negative effect on orange consumption in Japan.

• Orange prices in Japan dropped during 1987-95, the fi rst half of the 

period studied. Orange consumption increased until 1995, perhaps partly 

in response to the price drops. Price changes since 1995 have been slight. 

Orange prices have a signifi cant effect on consumption.

• The analysis revealed a strong trend away from orange consumption over 

time, which was not explained by the effects of demographic variables, 

prices, or household income. 
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How Was the Study Conducted?

The study relied on data from Japan’s Family Income and Expenditure 

Survey, which collects information on daily expenditures from 9,000 

households each month. The survey has gathered information on orange 

consumption since 1987. The data are reported based on age of the head 

of the household. Aggregate household orange consumption, rather than 

consumption by each household member, is reported. The study used detail 

on the ages of the members of each household to estimate consumption by 

individual members of different ages. These data were the basis for estimates 

of age/period/cohort effects. Estimates of consumption per person with 

the age and cohort (generation) effects netted out were used to investigate 

“period effects”: events, such as price and income changes, that could affect 

consumption in a given year. These time-series regressions (on own price, 

income, and a measure of time) determined an estimate of the price elasticity 

of oranges, as well as a time trend. 

Since income elasticity was not signifi cantly different from zero in the time 

series investigation, various cross-sections of the household data were sorted 

by income for further study. These cross-sections also failed to show a strong 

infl uence of income on orange consumption in Japan. Demographic variables 

were used to project consumption to 2017, to examine the extent to which they 

could lead to further declines in consumption, in the absence of other changes.
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Introduction

Most fresh oranges (oranges, hereafter) in Japan are imported, and the primary 

import source is the United States, which accounted for three-quarters of the 

total in 2004-06. Japan’s own citrus production consists principally of a kind 

of mandarin or tangerine that is not regarded as a close substitute for navel 

oranges.1 Japan liberalized its rules for imports of oranges as a result of the 

1988 Beef-Citrus agreement with the United States. After a 3-year transition 

period, Japan replaced existing import quotas with ad valorem tariffs in 1991.2

 The tariffs vary seasonally. Originally set at 20 percent for June through 

November and 40 percent for December through May, the tariffs were further 

reduced gradually to 16 percent and 32 percent, respectively, by 2000. 

Japan’s total imports of oranges, predominantly from the United States, 

increased steadily from about 111,600 tons in 1985 to 190,400 tons in 1994, 

the peak year, and then gradually declined to about 136,200 tons in 2000 and 

120,900 tons in 2006, respectively (table 1).3 During this period, Japan fell 

from the top overseas market for U.S. oranges to the third highest position. 

Consumption of oranges in Japan mirrors the product’s import history 

there. The most reliable source of information about orange consumption in Japan is the annual report of the Family Income and Expenditure 

Survey (FIES) by Japan’s Statistics Bureau (see box, “Family Income and 

Expenditure Survey”). Oranges, apart from mandarins and other domestic 

 1Partly because of seasonal import 

tariffs, which are higher in DecemberMay, there are strong seasonal differences in citrus consumption in Japan, 

with most mandarins consumed in 

October-February, and most navel oranges consumed in March-September. 

For more information, see Mori et al., 

2008.

 2See Mori et al., 2008.

 3Declines in imports in 1991 and 

1999 refl ected short supplies caused by 

harvest failures in California.

Table 1

Japan's imports of fresh oranges and country shares

 From:

Calendar year Total CIF price U.S. Chile S. Africa Australia

 Metric tons Yen/kg ————— Metric tons —————

1985 111,635 195.2 110,462 0 0 848

1986 117,300 140.9 115,968 0 0 938

1987 123,425 142.2 122,192 0 0 887

1988 115,347 141.6 114,810 0 0 482

1989 128,372 144.5 125,913 0 0 1,942

1990 145,188 143.7 143,118 0 0 1,833

1991 82,017 220.5 75,161 0 0 3,119

1992 171,701 114.2 166,398 0 1,518 3,366

1993 165,420 104.7 155,728 0 5,151 4,539

1994 190,376 99.7 182,517 0 3,667 3,668

1995 179,960 96.3 169,579 0 4,374 5,866

1996 154,086 111.5 135,683 38 5,905 11,960

1997 171,269 105.3 147,624 87 14,161 8,385

1998 150,470 117.7 131,866 25 9,210 7,357

1999 89,703 152.5 46,204 539 13,846 12,460

2000 136,150 82.3 116,951 1,153 8,547 6,245

2001 126,203 103.7 104,152 3,680 9,337 7,238

2002 103,873 105.1 79,611 4,958 8,028 8,765

2003 117,087 94.9 88,068 6,120 13,276 9,238

2004 112,937 97.2 85,524 10,408 10,216 6,493

2005 115,433 99.6 84,269 11,382 10,960 8,443

2006 120,875 113.0 88,179 9,440 7,714 15,522

Note: CIF means cost, insurance, freight.

Source: USDA, Economic Research Service, using trade data of Japan.
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citrus varieties, were fi rst itemized in FIES in 1987. As measured by FIES, 

per person, at-home consumption of oranges increased from 830 and 737 

grams (g) in 1987 and 1988, respectively, to 924-940 g in 1994-96 and then 

gradually declined to 533-585 g in 2005-06 (table 2). It is estimated that 

at-home consumption accounts for approximately 70 percent of the total 

distribution of oranges in Japan.4

Like consumption of oranges, consumption of fresh fruit in general has 

been declining steadily in Japan since the mid-1970s. Per capita at-home 

consumption of aggregate fresh fruit declined consistently from 49.7 kg 

in 1975 to 27.8 kg in 2006 (fi g. 1). Per capita consumption of mandarins 

declined from 19.97 kg in 1975 to 4.55 kg in 2006.

This report assesses various factors that may be related to the decline in 

at-home orange consumption in Japan since 1995. It is diffi cult to attribute 

the decrease to either an income or a price factor because neither factor has 

changed much in recent years. Living expenditures per person (a proxy for 

household income that is reported in FIES) in Japan increased slightly from 

1987 to 1995 and then remained at about the same level through 2006 (all in 

constant 2005 yen). The price index for oranges reported in the CPI declined 

from 153.3 in 1987 to 100.9 in 1996 (defl ated by 2005 aggregate CPI) and 

remained at the same level since then (fi g. 2).5

The real price index for fresh fruit (defl ated by aggregate CPI) increased 

slowly from 102.7 in 1975 to 108.1 in 1995 and then slightly decreased to 

104.0 in 2006 (2005=100) (fi g. 3). 

 4Ito, 2006: at-home consumption 

(FIES per person consumption times 

total population) is estimated at 60-65 

percent of imports. Ito surmises that 

10-15 percent of total imports may not 

be suitable for normal fresh marketing 

due to spoilage, and the like. At-home 

consumption of the marketable share 

would thus be about 70 percent.

 5Price spikes in 1991 and 1999 refl ected short supplies caused by harvest 

failures in California.

Table 2

Household purchases of fresh oranges in Japan

 Quantity Real price

 Per household Per person index1

 —————— Grams —————— 2005=100

1987 3,046 830 153.33 

1988 2,676 737 134.83 

1989 2,671 740 138.55 

1990 2,882 810 135.28 

1991 1,835 514 167.83 

1992 2,972 842 128.21 

1993 3,114 892 102.30 

1994 3,208 924 98.41 

1995 3,216 940 95.53 

1996 2,575 771 100.60 

1997 2,844 851 100.88 

1998 2,458 743 99.42 

1999 1,257 381 137.18 

2000 2,059 622 94.62 

2001 1,981 604 97.44 

2002 1,733 535 100.00 

2003 1,807 561 101.10 

2004 1,610 505 97.31 

2005 1,691 533 100.00 

2006 1,848 585 101.60 

1Orange Consumer Price Index (CPI) defl ated by CPI for all goods.

Source: USDA, Economic Research Service, using data from FIES, various issues.
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The Family Income and Expenditure Survey, or FIES, is used to depict households’ monthly fi nances and to produce basic statistical data on expenditures 

of all households by cities, regions, income classes, etc., for planning national 

economic and social policies. FIES has been conducted since 1946 with ongoing 

modifi cations but with time-series consistency maintained as much as possible.

The survey questions approximately 9,000 households, selected by random 

sampling from all consumer households in all prefectures of Japan, excluding 

one-person student households. Each household records daily expenditures for 6 

months and is then replaced by another household. Each month, one-sixth of the 

households are replaced.

For many food items, the survey records both expenditure and quantity purchased. 

In addition, it collects information relating to income and household composition 

and type. Results are conveyed in monthly and annual reports, published by the 

Consumer Statistics Division of the Statistics Bureau, Ministry of Internal Affairs 

and Communication.

Family Income and Expenditure Survey

Figure 1

At-home consumption of fresh fruit in Japan

Kg/person/year

Source: USDA, Economic Research Service, using FIES household survey data.

1975 1980 1985 1990 1995 2000 2006

0

10

20

30

40

50

60

Figure 2

Orange prices in Japan

Index, 2005 = 100

Notes: CPI = Consumer Price Index. 

Source: USDA, Economic Research Service, using data from the 

Statistics Bureau, Ministry of Internal Affairs and Communication, Japan. 

1985 87 89 91 93 95 97 99 2001 03 05

0

20

40

60

80

100

120

140

160

180

200

CPI, all Japan

Retail orange prices, deflated
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On the surface, it appears that at-home consumption of fresh fruit decreased 

markedly at the same time that income increased substantially (and then 

remained the same), while fresh fruit consumer prices did not change appreciably over the period. However, a previous study, which analyzed panel 

data by household types for 96,000 households annually from 1982 to 2001, 

demonstrated that fresh fruit is an income-positive good (Mori et al., 2006b)—

the wealthier the household, the greater the quantity of fresh fruit consumed. 

The consistent decline in fresh fruit consumption in Japan over the past three 

decades stems from factors that go beyond household income and price. So, 

too, does the decrease in orange consumption in the past decade.6

Based on recent fi ndings (Mori et al., 2006a; Mori et al., 2006b), this study 

hypothesizes that the decline in consumption might be at least partially attributed to generational change: more concretely, that today’s younger cohorts of 

Japan’s population have moved away from eating fresh fruit, and oranges as 

well, for unknown reasons (MAFF, 1995).

6See “Economic Analysis of Period 

Effects on Orange Consumption—Are 

Oranges Normal Goods in Japan?”, on 

page 14, for an economic analysis of 

orange consumption.

Figure 3

Real prices of fresh fruit and real household income in Japan

Index, 2005=100

Note: Fresh fruit CPI deflated by aggregate CPI. 

Source: USDA, Economic Research Service, using consumer price indexes (CPIs) 

from Japan's monthly CPI Report.

1975 1980 1985 1990 1995 2000 2006

0

20

40

60

80

100

120 Fresh fruit prices Household income
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Household Purchases of Oranges 

by Age of Household Head

Since 1979, FIES annual reports have included information on household 

purchases of various specifi c goods and services categorized by the age 

group of the household head (HH). As mentioned earlier, oranges were added 

to the survey items in 1987.

Examination of FIES data shows prima facie evidence of two effects on orange 

consumption (see selected years in table 3): individual aging and cohort effects. 

During 1987-2006, households with HHs in their forties, fi fties, and sixties ate 

substantially more oranges than those with HHs in their twenties and under age 

35. This is a pattern: as households age, they eat more oranges.

Also, data from the 1987 and 1990 surveys show that the households with 

HHs under age 35 bought fewer oranges than households with older HHs. 

In 2000-06, the HHs who were under age 35 in 1987 and 1990 were in their 

forties and their early fi fties. They still purchased fewer oranges than households headed by older HHs. This is also a pattern: tracing a cohort diagonally 

through table 3 reveals that the cohort generally purchases fewer oranges 

than older cohorts, and more oranges than younger cohorts.

The two patterns pertain to households categorized by the age of the HH 

and may not require further analysis: the FIES data give clear indications 

that cohorts of such households have different purchase levels for oranges, 

and that each cohort of households increases orange consumption as it ages. 

However, the household data by HH age group do not necessarily represent the 

consumption patterns over time by the same cohorts of individuals.

7 Individual 

consumption by age should be separated or derived from household data classifi ed by HH age groups. 

 7Deaton and Paxson, 1994; Deaton 

and Paxson, 2000.

Table 3

Household purchases of fresh oranges, by age of household head

HH age HH age

 1987 1990 1995 2000 2004 2005 2006

 Grams/year Grams/year

~24 1,027 774 627 906

25-29 1,300 1,136 1,483 880 ~29 497 874 445

30-34 2,161 1,789 1,576 879

35-39 3,163 2,473 2,306 1,504 30-39 765 780 927

40-44 3,299 3,310 2,958 1,962

45-49 3,427 3,610 4,067 1,933 40-49 1,450 1,310 1,475

50-54 3,553 3,455 3,480 1,938

55-59 3,046 2,890 3,128 2,663 50-59 1,905 1,879 2,109

60-64 2,880 2,915 3,656 2,297 60-69 1,901 1,957 2,069

65~ 3,186 2,694 3,904 2,706 70~ 2,312 2,385 2,601

average 3,046 2,882 3,216 2,077 average 1,648 1,691 1,848

Note: HH means household head.

~ means younger than or equal to, before a number, and older than or equal to, 

after a number.

Source: USDA, Economic Research Service, using data from FIES, various issues.
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Deriving Individual Consumption 

From Household Data 

The FIES data provide information on the number of members in the households surveyed and on total household purchases of various foods. The data 

do not provide information about how much each person in the household 

consumes. One way to estimate consumption per person would be to divide 

each household’s purchases by the number of people in the household 

(referred to as “simple division”). Another way would be to use additional 

information to estimate consumption by individuals of different ages. 

To illustrate these two approaches, assume that a three-person household 

headed by an adult in his/her mid-twenties (age 25) consumed 30 kg of some 

food, a four-person household headed by a middle-aged adult in his/her late 

forties (age 47) consumed 60 kg of food, and a three-person household headed 

by an old adult in his/her mid-sixties (age 65) consumed 80 kg of food.

One could estimate individual consumption by simply dividing household 

consumption by the number of persons in the household and assigning the 

result as individual consumption by an individual with the age of the household head. For example, consumption by the young adult age 25 should be 

30/3 = 10 kg; consumption by an adult age 47 should be 60/4 = 15 kg; and 

consumption by an older adult age 65 should be 80/3 = 26.7 kg. However, 

these results do not take into consideration the age variation among household members.

To show how information about the ages of household members can be 

used to estimate consumption, consider the households used in the previous 

example. The fi rst household may comprise two young adults and one infant, 

the second two adults in their forties and two young adults around age 20, 

and the third two older adults in their sixties and one adult in his/her thirties 

(e.g., age 32). Then, the analysis will have a set of equations as follows:

2X25 + 1 X0 = 30 (1)

2X47 + 2 X20 = 60 (2)

2X65 + 1 X32 = 80 (3)

where Xi

 denotes individual consumption by a person i years of age. 

The three equations have six unknowns, making it impossible to fi nd a solution. If it can be assumed, however, that infants do not consume this product: 

X0 = 0; people in their twenties and early thirties eat, on average, about the 

same amount: X20 = X25 =X32, then one will have the following solutions:

2X25 = 30 l X25 = 15 (vs. 10 by simple division)

2X47 + 2 ×15 = 60 l X47 = (60−30)/2 = 15 (vs. 15 by simple division) 

2X65 + 15 = 80 l X65 = (80−15)/2 = 32.5 (vs. 26.7 by simple division)

The simple division approach implicitly assumes that all members of the 

household are in the same age group as the HH, or, in an extreme example, 
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that infants eat as much as their parents. The FIES panel data of nearly 

96,000 households each year provide complete details on the age composition by HH age groups of the households surveyed.8

Using simple supporting constraints such as X0 = 0, X20 = X25 =X32, as above, 

one can obtain more realistic estimates of individual consumption by age 

from household data than from the simple division approach. 

With respect to the supporting constraints, the analysis uses the intuitively 

natural assumptions of gradual changes between successive age groups (i.e., 

the difference in consumption between individuals a year apart in age will 

be approximately zero (Xi

 − Xi+1 ≈ 0), which cover the entire range of age 

groups, instead of arbitrary a priori assumptions, such as X0 ≈ 0, X17 ≈ X22 , 

or X7 ≈ 0.6 X12).9 Individual consumption by age is estimated, minimizing the 

sum of squared residuals (4) and (5) below.10

Hj

 − ∑Cij Xi = Ej (i = 1-16 ; j = 1-10) (4)

Xk

 − Xk+1 = Ek (k = 1-15) (5)

where 

Hj : consumption by household headed by someone j years of age 

 Cij : number of individuals of i years of age in household with HH j years of age

Xi : estimated consumption by individuals of i years of age

Xk : estimated consumption by individuals of k years of age

Ej

, Ek : residuals

Table 4 provides estimates of annual individual consumption of oranges 

by age for the period 1987-2006. The estimates clearly demonstrate that 

individual consumption of oranges varies substantially by age throughout 

the survey period: generally, older people eat more oranges than younger 

people.11 This effect has intensifi ed over the period. In the late 1980s, individuals in their late thirties and older ate twice as many oranges as those 

in their twenties and younger, but by the middle of the 2000s, individuals 

in their late thirties through early fi fties decreased their consumption more 

than 50 percent, whereas those in their late sixties and older kept their 

consumption at the earlier levels. Also, most strikingly, children under age 

20 have reduced their consumption to one-tenth the level of people in their 

late sixties and older in recent years. Note that those in their forties in 2005, 

for example, were young adults in their twenties in the mid-1980s, those in 

their thirties in the mid-2000s were teenagers in the mid-1980s, and so on: 

everyone ages as time passes. Accordingly, this analysis uses an age/period/

cohort (A/P/C) model to separate estimated individual consumption by age 

into age, period, and generational cohort effects. 

 8These data are not usually available 

to the public but were made available for 

this study. The actual family age compositions by HH age groups are made public 

only partially in FIES annual reports, and, 

if then, on a sporadic basis. The data are 

much more complex than that illustrated 

in the example, and thus, may require 

diffi cult supporting constraints.

 9Hendrickson et al., 2001, pp. 107-08.

 10Mori and Inaba, 1997; Tanaka et 

al., 2004.

11Estimates for younger age groups, 

the early twenties and the late twenties 

in particular, are less stable or less dependable than those for older age groups 

above the thirties because the HH age 

groups under age 25 and age 25-29 (in 

recent years) are small in sample size. 

The estimates of nonadults under age 20 

are also not dependable because, unlike 

a married couple of two adults in the 

same age brackets, these individuals do 

not represent the principal components 

of age matrices of family structure by 

HH age groups, Cij, in equation (4). 

Also, they are more prone to be subject 

to the supporting constraints of gradual 

changes between successive age groups 

(i.e., X17 − X22 ≈ 0, X12 −X17 ≈ 0, 

etc.) in deriving individual consumption 

from the household data organized by 

HH age groups. 
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Table 4

Estimates of average individual consumption of fresh oranges 

in Japan, by age

 Age of consumers (in years)

 0~4 5~9 10~14 15~19 20~24 25~29 30~34 35~39

 Grams/person/year

1987 243 372 450 477 472 469 797 1,086

1988 277 390 448 398 381 403 526 1,128

1989 261 342 422 467 502 534 736 776

1990 197 340 486 534 477 439 634 861

1991 121 190 247 255 242 253 383 505

1992 225 361 514 577 594 563 594 813

1993 193 328 486 524 471 471 562 846

1994 104 181 304 414 489 535 597 803

1995 206 301 422 493 510 523 589 774

1996 165 247 337 382 384 392 471 869

1997 136 215 302 338 344 398 542 711

1998 60 112 169 212 265 336 425 778

1999 25 66 105 123 131 155 285 456

2000 139 183 238 278 317 356 410 497

2001 56 108 151 166 170 199 343 493

2002 25 47 87 134 187 243 305 389

2003 108 133 175 217 261 301 316 369

2004 17 53 108 156 192 221 278 375

2005 120 129 157 211 285 344 348 367

2006 7 45 84 126 163 199 326 447

 Age of consumers (in years)

 40~44 45~49 50~54 55~59 60~64 65~69 70~74 75 & older

 Grams/person/year

1987 1,124 1,210 1,272 1,167 1,163 1,265 1,281 1,207

1988 1,083 988 977 986 1,036 1,056 1,031 936

1989 935 1,016 1,139 1,150 1,035 1,083 1,080 999

1990 1,166 1,268 1,245 1,146 1,202 1,161 1,097 996

1991 623 685 754 765 895 927 915 862

1992 1,133 1,185 1,269 1,157 1,125 1,223 1,238 1,180

1993 1,188 1,281 1,191 1,314 1,390 1,401 1,370 1,281

1994 1,325 1,449 1,516 1,533 1,510 1,581 1,623 1,565

1995 968 1,146 1,217 1,260 1,591 1,716 1,777 1,746

1996 950 1,046 1,028 1,035 1,134 1,354 1,410 1,387

1997 945 1,086 1,147 1,375 1,510 1,601 1,649 1,619

1998 846 931 1,020 1,213 1,332 1,402 1,435 1,406

1999 510 551 558 603 609 617 624 609

2000 609 715 815 910 1,011 1,161 1,325 1,341

2001 627 732 817 910 1,020 1,168 1,318 1,342

2002 496 609 727 849 975 1,090 1,185 1,192

2003 459 553 648 742 847 1,071 1,336 1,392

2004 514 626 724 784 831 929 1,063 1,117

2005 411 505 639 735 821 940 1,082 1,139

2006 552 684 826 880 902 1,004 1,171 1,237

~ means younger than or equal to, before a number, and older than or equal to, 

after a number.

Source: USDA, Economic Research Service, using Tanaka et al. model with 

FIES household data.
9

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

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Decomposing Individual Consumption by 

Age From 1987 to 2006 Into Age, Cohort, 

and Period Effects

Applying the A/P/C analysis to the estimates of individual consumption 

by age group in table 4 allows for quantifying age effects for different age 

groups as such, cohort effects for different birth cohorts as such, and (pure) 

period effects for different years as such. This analysis uses the Bayesian 

cohort model fi rst developed by Nakamura (1986) and modifi ed by Clason 

(Mori, 2001). To overcome the “identifi cation problem” inherent in the linear 

additive A/P/C model (Mason and Fienberg, 1985), Nakamura introduced 

zenshintekihenka (gradual changes) between successive parameters for the 

entire range of each of three effects, instead of equality of a few chosen 

parameters of either age, cohort, or period effects (Rodgers, 1982; Smith, 

2004). These identifying constraints of zenshintekihenka are calibrated by 

hyperparameters ranging from 28 to 2-8 subject to ABIC (Akaike’s Bayesian 

Information Criteria). Mathematically, the Nakamura model can be expressed 

as follows:

Xit = B + Ai

 + PEt + Ck + Eit (6)

Xit : average consumption by person of i years of age at period t

B: grand mean effect

Ai

 : age effect to be attributed to age i years old

PEt

 : period effect to be attributed to period t

Ck

 : cohort effect to be attributed to cohort k 12 

Eit : random error

Minimize:

∑ −++ + [ ] X B A PE C it i t k ( ) 2 (7)

Minimize:

11 1

2 1

2

2 1

2

2 1

2

σσ σ A

i i

P

t t

C

ΣΣ Σ A A PE PE C C k k ()( )( ) −+ − + − + ++ (8)

ΣΣ Σ ii t t kk A PE C = == 0 (9)

In the particular case of oranges, where the differences in consumption per 

person between the younger and older age groups have widened in recent 

years (to the order of 1 to 10), the logarithms of Xit perform signifi cantly 

better than the untransformed variables. Table 5 provides estimates of age, 

period (annual year), and (birth) cohort effects on top of the grand mean 

effect, all in logs, which explain the changes in individual consumption of 

oranges by age from 1987 to 2006. For easier visual assessment, estimated 

cohort parameters in actual numbers are presented in table 6, although the 

statistical fi ts are substantially inferior. 

 12In the case of a standard cohort 

table, in which the survey period 

matches the age classifi cation, a cohort 

in a particular age cell moves down 

to the next age cell at the subsequent 

survey period—that is, every cohort follows a diagonal line in the table. In the 

data used by this study, age is classifi ed 

by 5-year intervals, and data are available for each year (period) from 1987 

to 2006. A moving average operator in 

the design matrix apportions the cohorts 

into annual age cells. Consider cohort k

in the ith age cell in 1987, for example. 

It is assumed that 20 percent of cohort 

k has moved to the next age cell (i + 

1) in 1988 and that the ith age cell in 

1988 comprises 20 percent of the next 

younger cohort (k + 1) and 80 percent 

of the remaining cohort k. Nakamura 

(1986) pioneered this general cohort 

analysis, and further details on the methods used in the current study are given 

in chapter 10, “Age in Food Demand 

Analysis” (pp. 323-34 in particular) in 

Mori (ed.), Cohort Analysis of Japanese 

Food Consumption (2001).
10

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

Economic Research Service/USDA

The data in table 4 cover all age groups from age 0 to 4 to age 75 and older. 

Using all the age cells from the youngest to the oldest provides more degrees 

of freedom in running the least square estimation of equation (7), subject to the 

identifying constraints of equation (8). However, previous research has shown 

that estimates of individual consumption by age are less stable for the younger 

age groups, particularly children under age 15.13 Including these young age 

groups could change the size of the period effects and, consequently, other 

effects in the row. Therefore, the three youngest age groups, 0-4, 5-9, and 

10-14, were excluded from this cohort analysis of orange consumption. 

13For example, Ishibashi, in two publications from 2007, found several cases 

of negative consumption estimates 

for the younger age groups, using 

methods and data similar to those 

used in this study. Also, for the case 

of ages 0-9, in particular, see Mori, 

Hiroshi, and William D. Gorman, 

“A Cohort Analysis of Japanese 

Food Consumption—Old and New 

Generations,” chapter 8 in Mori (ed.), 

2001, pp. 265-6.

Table 5

Changes in individual consumption of fresh oranges, decomposed 

into age, period, and cohort effects

 Age effects: Ai Period effects: Pt Cohort effects: Ck

Age groups

(years) Logarithm Calendar year Logarithm Years born Logarithm

15-19 -0.1725 1987 0.1123 ~ 1912 -0.1453

20-24 -0.2076 1988 0.0378 1913-17 -0.0783

25-29 -0.2221 1989 0.0693 1918-22 0.0206

30-34 -0.1494 1990 0.0933 1923-27 0.0949

35-39 -0.0534 1991 -0.1232 1928-32 0.1349

40-44 -0.0088 1992 0.1127 1933-37 0.1689

45-49 0.0050 1993 0.1167 1938-42 0.1781

50-54 0.0170 1994 0.1543 1943-47 0.1699

55-59 0.0415 1995 0.1347 1948-52 0.1695

60-64 0.0853 1996 0.0573 1953-57 0.1050

65-69 0.1518 1997 0.0860 1958-62 0.0450

70-74 0.2276 1998 0.0210 1963-67 -0.0065

75 ~ 0.2855 1999 -0.2561 1968-72 -0.0289

 2000 -0.0249 1973-77 -0.0614

 2001 -0.0830 1978-82 -0.1606

 2002 -0.1168 1983-87 -0.2599

 2003 -0.0895 1988 ~ -0.3459

 2004 -0.1229

 2005 -0.0930

 2006 -0.0862

Note: Grand mean effects = 0.7912 (original unit: 100 grams).

~ means lower than or equal to, before a number, and older than or equal to, 

after a number.

Source: Estimates from minimization exercise with original quantity data transformed 

into logarithms.
11

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

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Discussion of Age, Period, 

and Cohort Effects

Results of the A/P/C analysis (tables 5 and 6) indicate that the cohort effects 

are roughly as important as age effects and that both are substantially more 

important than “pure” period effects in explaining the changes in individual 

at-home consumption of oranges during the past decades in Japan. Period 

effects are the residual after the age and cohort effects are subtracted from 

the estimates of individual consumption at various ages. Period effects are, 

thus, not an ordinary time trend but a quantity variable unique to each year 

with age and cohort effects controlled. 

Japanese consumers eat more oranges as they age to the oldest group, 75 

and older, whereas those younger than the mid-thirties, in particular, eat 

substantially fewer oranges than those older than age 60. At the same time, 

the younger generations born after the mid-1960s are found to consume 

many fewer oranges than the older generations who were in their late thirties through sixties in the mid-1980s. For easier visual interpretation, the 

following examples draw on table 6. All consumers can be thought to begin 

with 782 grams, the grand mean of orange consumption over the whole 

sample. Membership in the age group 15-19 (column 1, table 6) is estimated 

to subtract 252 grams (g) from orange consumption, just by virtue of being 

young. Someone in the group age 75 and older is estimated to add 332 g to 

consumption. In addition to the other factors, birth cohort membership also 

Table 6

Changes in individual consumption of fresh oranges, decomposed 

into age, period, and cohort effects

 Age effects: Ai Period effects: Pt Cohort effects: Ck

Age groups

(years) Grams Calendar year Grams Years born Grams

15-19 -251.5 1987 146.6 ~ 1912 -165.2

20-24 -241.4 1988 7.7 1913-17 -20.5

25-29 -222.7 1989 41.2 1918-22 186.8

30-34 -143.3 1990 111.5 1923-27 255.0

35-39 -12.7 1991 -222.9 1928-32 301.1

40-44 50.6 1992 141.8 1933-37 302.8

45-49 40.6 1993 183.9 1938-42 256.4

50-54 9.1 1994 306.3 1943-47 181.7

55-59 1.3 1995 242.4 1948-52 133.8

60-64 44.4 1996 75.9 1953-57 -42.9

65-69 138.3 1997 177.8 1958-62 -154.7

70-74 255.4 1998 62.9 1963-67 -209.7

75 ~ 331.8 1999 -355.6 1968-72 -189.3

 2000 -63.5 1973-77 -187.3

 2001 -91.7 1978-82 -232.6

 2002 -154.7 1983-87 -184.2

 2003 -138.4 1988 ~ -231.2

 2004 -183.5

 2005 -175.6

 2006 -112.2

Note: Grand mean for the sample is 781.9 grams.

~ means lower than or equal to, before a number, and older than or equal to, 

after a number.

Source: Estimates based on minimization using original data (not transformed into logarithms).
12

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

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changes consumption (column 3, table 6). Membership in the peak orangeeating cohort, born in 1933-37, adds 303g to consumption. Membership in 

the cohort that eats the least oranges, born in 1978-82, subtracts 233g from 

consumption. Cohorts born before 1950 tend to eat, on average, 300~500g 

more oranges than those newer cohorts born after the mid-1970s. Those who 

will reach their forties in 2017 (born 1968-77) are predicted to eat 400g less 

oranges than those who were in their forties in the mid-1980s, for example. 

The period effects plus the grand mean show annual consumption per person, 

with age and cohort effects excluded. Comparison of the period effects plus 

the grand mean with the consumption per person derived by simple division 

shows that the two results moved in the same directions over time (fi g. 4). In 

all years, the period effect plus the grand mean is higher than the result from 

simple division. The difference is the contribution of the summed age and 

cohort effects, which must have been negative.14 

Changes in “pure” period effects derived from the A/P/C analysis seem 

to be slightly larger in absolute magnitude than those measured in simple 

consumption per person from the mid-1980s to the mid-1990s on the upward 

swing, and again somewhat larger in absolute magnitude from the mid-1990s 

to the mid-2000s on the downward swing. The aging of the population had a 

positive impact on total consumption, whereas the replacement of the older 

generations by younger generations had a negative effect (usually with a 

slightly larger absolute magnitude). On balance, it seems as if the demographic factors—population aging and generational replacement—mostly 

cancelled each other out in the case of orange consumption in the past two 

decades. However, will this continue to be the case in the future? 

Cohort effects are quite signifi cant in explaining the changes in orange consumption. Japan’s future economy is not easy to predict, but it is quite certain that the 

older generations born before the mid-20th century—fruit-eating cohorts—will 

be steadily replaced by newer generations who tend to eat relatively little fresh 

fruit, for unidentifi ed reasons. To illustrate the implications of cohort changes 

on orange consumption, the analysis simulates likely individual consumption by 

age to the year 2017, using the cohort parameters estimated earlier (see table 5 in 

logs). Table 7 projects individual consumption of oranges by age in 2007 

and 2017 (also in 2027, with less confi dence), synthesizing estimated cohort 

 14The comparison is made with the 

estimates using actual weights reported 

in table 6, rather than results from 

estimation using logarithms in table 5.

Figure 4

Orange consumption by individuals in Japan

Grams

Source: Mean plus period effects from weights reported in table 6 (rather than logarithmic 

values in table 5); simple division from household observations divided by number of persons 

in the household.

Simple division

Mean plus period effects

1987 89 91 93 95 97 99 2001 03 05

0

200

400

600

800

1,000

1,200
13

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

Economic Research Service/USDA

parameters: grand mean effect + age effect + period effects + cohort effects 

(and then transformed into actual numbers in grams). The period effects for the 

years 2007 and 2017 have not been determined, and it is assumed that they will 

remain at the 3-year average of 2004, 2005, and 2006. The cohort effects for the 

“newcomers,” who will be ages 15-19 and 20-24 in 2017, have not been estimated, and it is assumed that they will take the same values of the newest two 

cohorts, who were ages 15-19 and 20-24 in 2006.

In the mid-1980s through the mid-1990s, young Japanese under age 35 

consumed on average more than 50 percent fewer oranges than those in their 

fi fties and sixties (fi g. 5). The disparity between the young and the old in orange 

consumption has widened since then, with middle-aged adults also moving away 

from orange consumption. It is predicted that even those in their fi fties will eat 

less than half the oranges than those in their seventies will eat in 2017, if the 

demographic tendencies observed during the past two decades are assumed to 

continue. Trends illustrated in fi gure 5 suggest that the decline in at-home orange 

consumption since the mid-1990s will accelerate further in the decades to come.

Table 7

Individual consumption of fresh oranges by age groups

 Actual Projected Projected Projected

Age 1994-96 average 2007 2017 2027

 Grams/person

15-19 430 164 164 164

20-24 461 167 151 151

25-29 483 203 146 146

30-34 552 302 191 173

35-39 815 406 300 216

40-44 1,081 473 417 263

45-49 1,214 550 464 342

50-54 1,254 649 502 442

55-59 1,276 797 598 504

60-64 1,412 882 760 586

65-69 1,550 1,048 1,028 769

70-74 1,603 1,222 1,225 1,052

75 and up 1,566 1,291 1,426 1,394

Note: Period effects for the future years are assumed constant at the 2004-06 average.

Source: Synthesis of estimated cohort parameters in table 5.

Figure 5

Individual orange consumption in Japan by age group

100g/person/year

Source: USDA, Economic Research Service.

2017 (proj.)

2007 (proj.)

1996-98

1987-88

15-19 20-29 30-39 40-49 50-59 60-69 70+

0

2

4

6

8

10

12

14

16

Age (years)
14

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

Economic Research Service/USDA

Economic Analysis of Period Effects on 

Orange Consumption—Are Oranges Normal 

Goods in Japan?

1. Time-series approach

Japan’s orange imports nearly doubled from the mid-1980s to the mid-1990s 

and then gradually declined to the level of 20 years ago in the mid-2000s (see 

table 1). Household consumption of oranges as reported in FIES followed 

the same pattern over the period. Did economic variables, such as price and 

income, infl uence these patterns?15

When simple per person consumption of oranges (from FIES, using the 

simple division method) is regressed against real living expenditures per 

person (as a proxy for income—from FIES) and real prices (the price index 

as reported in CPI surveys), over the years 1987 to 2006, the following estimates are obtained for income and price elasticities: 

log (CapQt

) = 4.71 ⎯ 0.16 log (CPI Pt) ⎯ 0.51 log (LEXt) (10)

 (0.58) (-0.41) (-0.20) R2 = 0.0097

where:

CapQt

 = consumption per person in the year t

CPI Pt = real price reported by the CPI in the year t (defl ated by aggregate

 CPI, 2005 = 100)

LEXt = real living expenditures per person in the year t (defl ated by the 

 aggregate CPI, 2005 = 100)

The numbers in parentheses denote t-values. 

The result indicates that the changes in orange consumption per person during 

1987-2006 are not explained by the economic factors, own price and household 

income. This was anticipated, as discussed in an earlier section. Consumption 

per person fell after the mid-1990s, while both real price and real income 

remained nearly the same over the corresponding period. When consumption was regressed on real price, and only on the fi rst 10 years, from 1987 to 

1996, however, the own price is a signifi cant variable in explaining orange 

consumption, with the expected negative sign: an own price elasticity around 

-0.6. The income variable, however, is still not signifi cant when consumption is 

regressed against it. See the regression equations, (11) and (12). 

 log (CapQt

) = 4.20 ⎯0.62 log (CPI Pt) (11)

 (9.57) (-2.97) R2 = 0.5250

log (CapQt

) = 1.02 + 0.62 log (LEXt) (12)

 (0.21) (0.38) R2 = 0.0181

Data refl ect the 10 years from 1987 to 1996.

 15Prices of possible substitutes were 

not included because most fresh fruits, 

including the domestically produced 

mandarin oranges, showed declines in 

consumption similar to or greater than 

those of oranges over this period, and 

because the annual series of observations is relatively short, making estimation with a larger number of variables 

diffi cult. See Mori et al., 2008, for 

further discussion of possible substitutes for oranges.
15

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

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It was stated in the previous sections that the changes in orange consumption 

in Japan for the past two decades could be attributed partially to demographic 

factors, the aging of the population having a likely positive impact and the 

replacement of the older cohorts by the new having a negative impact. If the 

period effects estimated in the cohort analysis (the second columns in tables 

5 and 6) represent the net period effects in orange consumption free from the 

demographic factors, price and income elasticities should be more accurately 

determined by using the period effects plus the grand mean as a dependent 

variable in regression analysis like that shown earlier (Mori et al., 2006a). 

The period effects, unique for each year, should refl ect the infl uence of price 

and income changes on consumption in that year, as well as of other events 

or changes.

log (PEt

 +GM ) = 3.08 ⎯0.08 log (CPI Pt) ⎯ 0.69 log (LEXt) (13)

 (0.35) (-0.20) (-0.26) R2 = 0.0042

where:

PEt

 = period effects for the year t, 1987 to 2006

GM = grand mean effect

Results for equation (13) reveal little, other than that the economic variables do not explain changes in orange consumption from the mid-1980s to 

the mid-2000s, even after accounting for the demographic impacts. When 

the fi rst 10 years from the mid-1980s to the mid-1990s are examined, the 

following regression equations, (14) and (15), demonstrate that own price 

may account for some of the steady increase in orange consumption from 

1987 to 1996, at an estimated own price elasticity of around -0.6, whereas 

income can not be deemed statistically accountable for changes in consumption, at least for the period in question. 

log (PEt

 +GM) = 2.06 ⎯0.57 log (CPI Pt) (14)

 (4.03) (-2.34) R2 = 0.4062

log (PEt

 +GM) = 0.21 + 0.22 log (LEXt) (15)

 (0.04) (0.13) R2 = 0.0020

where:

PEt

 = period effects for the year t, 1987 to 1996

GM = grand mean effect

The same regression efforts show no signifi cant results for the later period of 

the data, 1997-2006. As mentioned earlier, Japan’s economy has been quite 

stagnant until recently. Household fi nal consumption expenditures changed 

slightly from 268 trillion yen in Japan fi scal year (JFY) 1995 to 278 trillion 

yen in JFY2000, and 287 trillion yen in JFY2003 (all in constant 2000 yen). 

Thus, the steady decline in actual household orange consumption since the 

mid-1990s and the substantial declines in (pure) period effects from 1994 

(second column, tables 5 and 6) are being contrasted to gradual and small 

shifts in income (recall that the price of oranges remained the same in trend 
16

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

Economic Research Service/USDA

during the past decade since the mid-1990s, fi g. 2). Factors other than income 

and/or price effects may have led to the steady reduction in Japan’s orange 

consumption in the past 10 years.

One hypothetical explanation is that the increase in consumption of 

bottled nonalcoholic drinks replaced the expenditures on fresh fruit. 

Starting in the mid-1990s, a “PET-bottle culture”16 took root in 

Japan, and among young people in particular. Production per capita of 

PET-bottled or canned tea drinks, mainly Chinese tea and Japanese green 

tea, soared from under 2 liters in 1985 to 12 liters in 1990, 24 liters in 

1995, 35 liters in 2000, and 44 liters in 2005. Over the same period, 

production (=consumption) of soda drinks and fruit drinks did not change 

appreciably, whereas that of PET-bottled mineral water followed the 

same growth pattern as tea drinks (fi g. 6). The price of a bottle or can of 

tea drink (350-500 cc) is about the same as the price of one orange, apple, 

peach, or a large-sized mandarin. 

It is diffi cult to consider PET-bottled soft drinks directly in the category 

of substitutes for fresh fruit, including oranges. However, it is clear that 

some forces unfavorable to fresh fruit consumption in the Japanese market 

have been present during the past decade or so. Adding a simple straight 

time trend to the regression equations (10) and (13) allows for obtaining 

the following results of equations, (16) and (17). The results suggest that 

income elasticities for oranges are not statistically different from zero; that 

is, oranges are not deemed either an inferior or a normal good, whereas the 

own-price elasticity is about -1.4, with substantially improved t-values and 

coeffi cients of determination. 

log (CapQt

) = 8.40 ⎯1.37 log (CPI Pt) + 0.25 log (LEXt) ⎯1.42 log T (16)

 (2.47) (-6.57) (0.24) (-9.16) R2 = 0.8416

log (PEt

 +GM ) = 6.80 ⎯1.39 log (CPI Pt) + 0.21 log (LEXt) ⎯1.54 log T (17)

 (1.99) (-6.55) (0.20) (-9.68) R2 = 0.8547

 16PET is an acronym for polyethylene 

terephthalate. PET bottles are commonly 

referred to as plastic bottles.

Figure 6

Bottled beverage production in Japan

Liters/person/year

Source: USDA, Economic Research Service, using Japan Soft Drinks Association, 

Annual Report, various issues.

Soda pop

Mineral

Tea drinks

Fruit juice

Total

1985 87 89 91 93 95 97 99 2001 03 05

0

10

20

30

40

50
17

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

Economic Research Service/USDA

where:

T = trend dummy starting from 10 at 1987 to increase by 0.5 annually

Data are from 1987 through 2006.

The time trend is quite signifi cant. Its coeffi cient, -1.5 in equation (17), illustrates the generally declining values of the trend over time. In general, each 

succeeding year has a smaller period effect or a negative period effect in 

1995-2006 (fi g. 7).

2. Cross-sectional approach

Differences in demand for oranges can also be seen in a cross-section of 

households at a given time, as well as in averages of households over a 

period of years (as examined earlier). Access to the FIES panel data of 

oranges and beef classifi ed by household types provides other opportunities to investigate income effects while circumventing the age factors in 

consumption (Mori et al., 2006b). 

This approach uses the data for four major household types: a married 

couple with HH in the thirties and two children under age 10; a married 

couple with HH in the forties and two teenagers; a married couple with HH 

in the fi fties and one child in the twenties; and a married couple with HH 

in the sixties with no dependents. Each household type includes approximately 2-4,000 samples. 

Every household reports monthly purchases of various commodities, including 

oranges, and annual incomes earned during the 12 months prior to the survey 

month. This analysis uses the 6 months from March through August because 

the other months are less important for orange consumption in Japan. 

Following the lead of Prais and Houthakker,17 simple double-log regressions of average consumption (monthly purchases) were run against annual 

incomes by selected income groups, excluding extremely low and high 

incomes (roughly the bottom and top 5 percent, respectively).

 17See pp. 79-108.

Figure 7

Period effects on orange consumption in Japan

100g/person/year

Source: Values are from estimates contained in table 7.

1987 89 91 93 95 97 99 2001 03 05

-4

-3

-2

-1

0

1

2

3

4
18

Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

Economic Research Service/USDA

For 1987, oranges are found to be income positive for all household types, 

with the elasticity ranging from 0.4 to 0.6, signifi cantly different from zero 

(table 8). In other years, 1999 and 2001, for example, the elasticities vary 

from zero to greater than 1.0. For 1997, the estimates are found to be insignifi cant except for the age group of HHs in the sixties. Generally, oranges are 

estimated as income positive, but statistically the estimates are not conclusive 

and not consistent over the period 1987-2006.

As an additional approach, all households are classifi ed into income-quintile groups, by four HH types. Within each quintile group, households are 

arrayed according to the amount of monthly purchases, from zero to 5 kg 

of oranges in 2001 (households that purchased more than 5 kg of oranges 

account for less than 0.5 percent of all households in any household type and 

are deemed “outliers”). In table 9, the share of households reporting zero 

purchases in any specifi c month is found in the fi rst row in each household 

type. The second row provides the average of monthly purchases by those 

households that reported more than zero consumption.

Table 10 provides the cross-sectional fi ndings enumerated in the same 

manner for beef in 1997.18 The percentages of zero (monthly) purchases 

are 10 to 30 percent, substantially smaller than the case of oranges, which 

average slightly over 80 percent. The differences between the two cases are 

striking: fi rst, the percentage of zero purchases tends to decline as the group 

income increases for beef, whereas the zero percentage does not vary by 

income group for oranges; second, the average size of monthly purchases 

by those households which recorded purchases greater than zero tends to 

increase as the group income increases for beef, whereas that for oranges 

does not vary by income group. 

It may be safe to conclude that beef should be truly a “normal” good in 

two senses: as income increases, more households tend to buy beef and in 

 18The year 2001 was not selected 

for beef because of outbreaks of BSE, 

or bovine spongiform encephalopathy, 

that year.

Table 8

Estimates of cross-sectional income elasticities for oranges derived from panel data classifi ed 

by household types

Ln(Q) = a + b Ln(Y) (1)

Age of household 

head 30s 40s 50s 60s

Age of spouse 30s 40s 50s 60s

Age of children Under 10 10-20 20s

Number of children 2 2 1 0

Income

elasticity

Adjusted

R2 t-value Income

elasticity

Adjusted

R2 t-value Incomeelasticity

Adjusted

R2 t-value Incomeelasticity

Adjusted

R2 t-value

1987 0.39 0.17 1.84 0.64 0.45 3.55 0.44 0.1 1.68 0.45 0.20 2.02

1989 1.39 0.70 4.47 0.62 0.22 2.11 0.79 0.34 3.23 0.18 0.05 1.32

1991 0.37 0.06 1.40 0.86 0.40 3.02 0.99 0.44 3.11 0.07 -0.06 0.29

1997 0.38 0.02 1.11 0.18 -0.02 0.77 -0.04 -0.05 -0.14 0.65 0.38 3.17

1999 1.25 0.41 3.04 0.06 -0.1 0.08 0.79 -0.04 0.72 0.25 0.07 1.56

2001 1.44 0.61 4.05 1.03 0.24 2.45 -0.04 -0.05 -0.14 0.25 0.03 1.30

Note: Q = monthly household purchase; Y = annual household income; b = income elasticity; t-value is for the parameter b.

Source: USDA, Economic Research Service, using equation (1). Households in each household type are grouped by every 0.5 million yen in 

annual income.
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Declining Orange Consumption in Japan: Generational Changes or Something Else? / ERR-71

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greater amount on average. In contrast, oranges are not income-related in 

any sense: the share of households that purchases oranges may not respond 

positively to the increase in average income of the group, and the mean 

of household purchases may not increase as income increases. Crosssectionally, oranges are deemed to be neither a “normal” nor an “inferior” 

good in terms of economics. 

Table 9

Household monthly fresh orange purchases by income quintile; 

frequency of zero-purchase households and average amount of 

monthly purchases by those registering more than zero purchases 

in each month, March to August, 2001

 Income quintile groups

 I II III IV V

 Parents in 30s and two children under 10:

Zero-purchase households (percent) 89.95 90.23 88.69 86.69 85.85

Average amount of purchases by 

 nonzero households (kg) 1.023 0.922 1.088 1.113 1.333

 Parents in 40s and two teenagers:

Zero-purchase households (percent) 85.52 80.92 81.63 77.03 84.45

Average amount of purchases by 

 nonzero households (kg) 1.064 1.242 1.233 1.191 1.383

 Parents in 50s and one child in 20s:

Zero-purchase households (percent) 81.13 83.11 81.13 79.8 84.44

Average amount of purchases by 

 nonzero households (kg) 1.249 1.169 1.107 1.482 1.106

 Parents in 60s with no dependents:

Zero-purchase households (percent) 86.53 80.53 82.13 81.73 83.2

Average amount of purchases by 

 nonzero households (kg) 1.334 1.476 1.434 1.412 1.532

Source: USDA, Economic Research Service, using FIES panel data.
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Table 10

Household monthly beef purchases by income quintile; frequency of 

zero-purchase households and average amount of monthly purchases 

by those registering more than zero purchases in each month, 1997

 Income quintile groups

 I II III IV V

 Parents in 30s and two children under 10:

Zero-purchase households (percent) 24.3 22.5 18 19.5 15.8

Average amount of purchases by 

 nonzero households (kg) 0.887 0.891 0.901 1.021 1.091

 Parents in 40s and two teenagers:

Zero-purchase households (percent) 11.3 7.2 9.5 9.5 9.5

Average amount of purchases by 

 nonzero households (kg) 1.633 1.493 1.599 1.674 1.787

 Parents in 50s and one child in 20s:

Zero-purchase households (percent) 14.5 15.2 14.6 14.6 15.4

Average amount of purchases by 

 nonzero households (kg) 1.215 1.148 1.147 1.134 1.175

 Parents in 60s with no dependents:

Zero-purchase households (percent) 38.9 34 32.6 30.8 26.5

Average amount of purchases by 

 nonzero households (kg) 0.792 0.76 0.786 0.822 0.937

Source: USDA, Economic Research Service, using FIES panel data.
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Conclusions 

The orange market in Japan, largely supplied by U.S. growers, has declined 

since the mid-1990s. Declining consumption per person is diffi cult to explain 

using the effects of income and price changes. Consumption per person, 

defi ned as simple division of household consumption of oranges by all 

household members, ignores differences in age, which may affect consumption. In fact, it is readily apparent that both age and cohort membership affect 

household orange consumption in Japan. 

Both cohort and age effects are found to be strong. As individuals age, they 

generally eat more oranges per year, according to this analysis. Membership 

in a decadal birth cohort that was born in the fi rst half of the 20th century 

is associated with relatively high levels of orange consumption; decadal 

birth cohorts since the mid-20th century have consumed progressively fewer 

oranges. These two demographic effects have tended to cancel each other out. 

The Japanese market is quite important to U.S. producers. This investigation 

indicates that consumption of oranges may decline further, both as a result 

of an unexplained, but strong, negative time trend and as a result of generational changes: as today’s older cohorts die off, U.S. oranges are losing 

their best customers. 

It appears that the price of oranges does matter to consumers in Japan. 

Reducing or eliminating tariffs could lead to lower orange prices in Japan. 

Also, reductions in the margin between import and retail prices would lead 

to lower retail prices. Substantially reduced retail prices of oranges might 

appeal particularly to young households, which typically have lower incomes 

among all households in the Japanese labor market. 

Japan’s household consumption data provide an excellent opportunity 

to study consumer behavior. In the case of consumption of fresh fruits, 

including oranges, it appears that systematic, age-related changes are 

underway that lead to lower consumption of foods that are generally regarded 

as good for health. Further studies of consumption of fresh fruits and other 

foods in other countries may also show strong effects of age and cohort 

membership. Studies establishing the presence and extent of such effects can 

provide the basis for consumer surveys that examine why these effects occur 

and what marketing steps might be effective in addressing them. 
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