SOME EXPERIMENTATION WITH RECALL PROCEDURES AND DIARIES FOR CONSUMER EXPENDITURES

Seymour Sudman and Robert Ferber, University of Illinois at Urbana-Champaign

The importance of consumer expenditure information 

for government planning and econometric analysis is 

unquestioned. Since procedures for collecting this 

information vary from country to country, additional 

methodological research is needed to determine the 

procedures that yield the most valid results. We report 

here on three studies conducted by the Survey Research 

Laboratory of the University of Illinois.

The first study explored the effectiveness of 

various recordkeeping forms and panel recruiting 

procedures for obtaining information on frequent 

nondurable expenditures, such as food, groceries, drugs 

and meals eaten away from home. This was a precursor to 

a larger methodological study by the U. S. Bureau of 

Labor Statistics and to a large national study of 

consumer expenditures scheduled to start soon.

The aims of this study were:

1. To develop recordkeeping formats and 

related materials after reviewing the 

literature and the experience of panel 

operators in the United States and Canada.

2. To test format effects on sample 

cooperation, completeness of reporting 

and accuracy of purchase details.

3. To test the effect of different time 

periods for recordkeeping and gifts on 

sample cooperation and reporting, as well 

as other methods of stimulating response.

Methodology

Diary Forms

Three diary forms were tested. On all three forms 

information was obtained on the date of purchase, the 

item or service, the number of items, the size or 

weight per item, the price per item per pound, the 

total price and whether sales tax was included. The 

forms differed in how they were structured:

1. Journal Diary. In this form purchases were 

entered in the order in which they were made. No product 

categories were given in the diaries. A Checklist of the 

products or services to be included was given at the 

front of the diary.

2. Outlet Diary. This form was arranged by type of 

stores or services. Four pages were a1lowed for 

purchases made in food and grocery stores, and single 

pages or parts of pages for auto supply outlets, gas 

stations, drug stores, restaurants, bars, clothing or 

shoe stores, variety stores, etc.

3. Product Diary. This form was arranged by product 

group, such as milk, dairy products, eggs, cheese; meat, 

fish, poultry; fresh fruit, vegetables; bread, bakery 

products; beer, wine, liquor, soft drinks, etc. No 

outlet information was obtained.

Variations of these three diaries have been used 

previously. The open journal diary is used in most 

Common Market and Latin American countries. It has the 

advantage that the respondent need not search for the 

page of the diary on which to make an entry. The 

disadvantage is that the generalized headings and 

instructions may not cover all situations and may cause 

the respondent to worry about recording her purchases 

correctly.

The outlet and product diaries reverse the 

advantages and disadvantages of the journal diary. The 

product diary has been used in Canada and Great Britain. 

It requires the recordkeeper to decide whether, for 

example, frozen fish sticks should be included under 

meat, fish and poultry or under canned, frozen and 

packaged goods. Though there is little or no harm in 

processing the diary if a product is misclassified, the 

respondent may again be concerned.

The outlet form, though never used before to our 

knowledge, is based on research by MRCA and the Life 

Survey of Consumer Expenditures that suggests when 

respondents recall expenditures, they should first recall 

where they shopped and then what they purchased there. 

Like the product diary, the outlet form is subject to 

classifying errors, particularly for stores that sell 

groceries, drugs and clothing under a single roof. In 

addition, there may be classifying problems with the gas 

station that sells milk or the grocery store that sells 

toys, newspapers and fertilizer.

Time Period

The sample was divided into four equal subsamples 

for testing time periods of one, two, three and four 

weeks. The advantages of the longer time periods are in 

the more reliable picture of expenditures during the 

first period (Kemsley and Nicholson, 1960). 

Unfortunately, sample cooperation declines and sample 

biases increase as the recordkeeping period increases. 

The optimum period is one that minimizes the total error 

composed of recordkeeping errors and sample biases.

Compensation

Operators of continuing commercial panels are 

convinced that some continuing compensation in the form 

of gifts is required to maintain cooperation. The United 

States Government, however, has never paid respondents 

for participating in surveys. Given this constraint, we 

attempted to test the effect of three different rewards 

on cooperation and the accuracy of recordkeeping. In 

Springfield, half the cooperating households received a 

padded stationery holder with a retail value of about 

$5.00 as an immediate gift when they agreed to keep the 

diary. The stationery holder was used to hold the diary 

and purchase records during the recordkeeping period but 

was then kept by the family. The other half of the 

cooperating households in Springfield were offered a 

report at the end of the study that would compare their 

purchase patterns with those of other panel households

with similar incomes.

In Rock Island half the households were offered
their choice of an American flag, a series of historical 

posters or two books from a list of about 40 popular 

books on the Government Printing Office list. The other 

half, who acted as controls, were not offered a gift but 

were given a black plastic folder valued at about $1.00 

in which to keep the diary and purchase records. They 

were allowed to keep this folder at the end of the 

recordkeeping period.

Sampling and Field Work

The study was conducted primarily in the 

Springfield and Rock Island, Illinois Standard 

Metropolitan Statistical Areas. A probability sale of 

households was selected using city and phone 

directories, and the principal food shopper in the 

household was interviewed.

The time period for the main field work was May 

through July 1969. A total of 29 interviewer twelve each 

in Springfield and Rock Island and five in Decatur were 

trained, and 25 interviewers carried out their 

assignments. Interviewers were trained at group 

meetings, studied at home and completed a practice 

interview. At the debriefing sessions after the study 

the interviewers reported that most respondents had been 

highly interested in the topic of how they spent their 

money. There was little reluctance to report expenditure 

information. Almost all refusals were because the respondent was too busy or because she did not understand 

how to keep the form.

Results

As one would expect, level of cooperation drops 

sharply during the four week period. About 85 percent 

of interviewed households kept a diary for at least one 

week, while less than 50 percent kept it for four 

weeks. (Table 1)

The diary formats had an unexpectedly large effect 

on cooperation, particularly as the length of the 

recordkeeping period increased. Cooperation was highest 

on the product diary, lowest on the journal diary. The 

outlet was slightly but consistently lower than the 

product diary. (Table 2)

The offer of a gift had a slightly positive 

effect for respondents returning at least one diary and 

a much larger effect on those returning four diaries. 

The immediate gift of the stationery holder obtained 

the highest initial cooperation, but the delayed gifts 

obtained the highest cooperation for four weeks. This 

suggests that if a four week period is used, an 

effective strategy would be to give the recordkeeper 

both an initial and a delayed gift. (Table 3)

Completeness of reporting showed exactly the same 

relationships as did cooperation. The reported levels of 

expenditures were highest on the product diary, lowest 

on the journal diary. (Table 4) The time period effect 

was most noticeable in the fourth week when there was a 

very sharp decline in level of reported expenditures. 

The differences between the first week and the second 

and third weeks was not as large as had been expected, 

but there was some evidence that households purchased 

more heavily in the first week and bought less in the 

second week as they used up their first week stocks. 

(Table 5)

There was not much difference in the level of 

reported expenditures among the three gifts, but 

households that received no gift reported at a 

significantly lower level. (Table 6)

To summarize our conclusions:

1. The collection of data about frequently 

purchased items by use of a diary is not only 

feasible but is also more likely to result in 

lower cost information than would the use of 

long recall surveys.

2. Weekly diary records produce estimates of 

purchase expenditures for groceries, drugs and 

clothing that are in close agreement with 

sales tax estimates. Purchases of furniture 

appear to be overestimated while food eaten 

away from home is substantially 

underestimated.

3. The optimum time period based on cooperation and level of reported expenditures is two or three weeks.

4. The product diary is preferred over the 

journal and outlet diaries because it 

achieves a higher level of cooperation, 

better reporting and is also more easily 

processed.

5. A gift can increase panel cooperation and 

significantly improve the level of 

reporting.

The second study tested the accuracy of recall of 

durable and other goods for periods of 3, 6 and 12 

months. In addition, differences in recall of clothing 

purchases by the household informant and individual 

household members were also measured. The study was

conducted during the period January through March 1970 

in the Decatur, Rock Island, and Springfield, Illinois 

Standard Metropolitan Statistical Areas. The sample was 

not a random sample of the population, but was selected 

so that verification from outside sources would be 

possible.

The results of the validation procedure agree with 

the internal analysis of responses and with the 

general literature on forgetting. The chief findings 

are as follows:

1. There is a sharp decline in reported recall 

of durable purchases as the recall period 

increases. The average number of purchases 

reported in the twelfth month is 78 percent 

less than the number reported in the first 

month.

2. Larger items such as furniture, rugs, 

draperies and appliances are better 

remembered than less costly durable goods, 

but recall also drops sharply for them as 

the recall period increases. Based on 

validation data these large ticket items are 

underreported by 11 percent for 3 month 

recall, by 41 percent for 4-6 month recall, 

and by 47 percent for 7-12 month recall. 

(Table 7)

3. Clothing purchases show a strange 

reversal of this trend. Based on 

validation data recall of clothing 

purchases appears to be better for
longer than for shorter periods. It 

is possible that telescoping effects 

are larger for clothing than for 

other durable goods and cancel out 

the forgotten items. (Table 7)

4. Hosiery and underwear are reported most 

accurately, with an average bias of 3 

percent for the total sample and period. 

These items were reported on a form filled 

in by the respondent in the middle of the 

interview. This result along with recent 

Australian experience suggest that the use 

of self-administered forms may help to 

improve recall of durables. (Table 7)

5. Validation results for expenditures for 

automobile supplies and services indicate 

that recall for these items declines as the 

time period increases, as is true with 

other durable goods. This is so even though 

these items were also obtained by the selfadministered form rather than by direct 

interviewing. Estimates for weekly 

expenditures for gas and oil, on the other 

hand, appear to be overstated. (Table 8)

6. Unlike other product expenditures, insurance 

premium expenditures are better collected 

annually than quarterly. Households reporting

for premium expenditures for 12 months 

recall averaged one-third higher for life 

insurance, twice as high for automobile 

insurance and three times as high for fire

insurance as households reporting for 3 

months. There are no dif ferences, however, 

for health and medical insurance where 

premiums are usually paid on a monthly or

quarterly basis. Validation comparisons 

indicate that net reporting biases are near 

zero and that insurance payments are

more accurately reported than are

purchases of durable goods. (Table 9)

7. The wife is the single best respondent for 

a household survey of durable goods. Total 

quarterly purchases reported by husbands 

are about two-thirds of those reported by 

wives. Joint interviews with husbands and 

wives, which were conducted only at the 

request of the household, do not result in 

recall either much better or much worse 

than that obtained from the wife alone.

8. As expected, individual self-reports of 

clothing purchases are about 15 percent 

higher than those by the household informant 

for 3 month recall. For 6 or 12 months the 

differences are about 5 percent, suggesting 

that either everyone's memory has gotten 

worse or through time the housewife becomes 

more aware of what household members have 

purchased.

9. Forgetting does not appear to be uniform over 

demographic characteristics. Generally 

households making more purchases have a 

sharper decline in recall as the time period 

lengthens. Thus, larger households with three 

or more members and households above the 

median income show sharp declines in the 

levels of recall in months 2 and 3 as compared 

to month 1, while other households do not 

decline as much. The differences between 

groups are smaller for longer time periods, 

although overall results are worse. Recall 

also becomes worse as the age of the household 

head increases, but education does not have 

any effect independent of income.

The general pattern of forgetting that emerges from 

this study of durable goods is much like that for more 

frequently purchased non-durables. This is 

disappointing, but additional measures may improve 

reporting. Bounded recall procedures can certainly limit 

the degree of telescoping. Forgetting a purchase 

entirely is more difficult to control, but the use of 

inventory methods may help. Diaries for durables or 

self-administered forms for recall should also be 

tested.

Keeping a written record is a chore for virtually 

everybody and becomes impossible in households where 

no one is literate. One would expect that both 

cooperation and accuracy of reporting would decline 

with decreasing education of the respondent. Thus, 

diaries for measuring consumer expenditures which are 

used in middle class areas might not be feasible in 

lower income areas in the inner city.

An alternative suggests itself--the use of tape 

recorders to obtain purchase information as the item is 

brought into the house without requiring any written 

records. We now summarize the results of two small 

experiments in Decatur and Chicago, Illinois with the 

use of tape recorders, and compare levels of 

cooperation and of reporting between tape recorders and 

diaries.

The findings of the experiments are mixed. In both 

cities, households were willing and able to report 

purchase expenditures on tape, but there were no 

significant differences in level of cooperation between 

diaries and tapes. In Decatur, in a predominantly middle 

class area the level of reporting was higher for tapes 

than for diaries. In the lower income area in Chicago, 

the reverse was the case. With some Chicago tape 

recorder respondents the results suggested that some 

kind of written record was kept and that the report was 

made on tape at the end of the week from the written 

record.

Since the tape recorders make coding more difficult 

as well as requiring additional funds for their

purchase and maintenance, one would make extensive use 

of them only if they were clearly superior to diaries. 

On the evidence to date, this is not clear.