METHODOLOGICAL RESEARCH IN THE CONSUMER 

EXPENDITURE SURVEY PROGRAM 

Clyde Tucker, Bureau of Labor Statistical 

ABSTRACT 

This paper reports on two research projects 

involving the CE Diary Survey. One project, 

almost completed, examines the attitudes 

and record-keeping behavior of diary 

respondents. The other project, still in 

the data-collection phase, is an experiment 

to evaluate alternative diary formats. The 

paper discusses the reasoning which led to 

these projects and various aspects of their 

designs. 

INTRODUCTION 

Survey methods can always be improved. The 

Consumer Expenditure Survey Program 

supports ongoing methodological research 

designed to improve the quality of the CE 

data. This paper reports on two such 

research projects involving the CE Diary 

Survey. One project, almost completed, 

examines the attitudes and recordkeeping 

behavior of diary respondents. The other 

project, still in the data-collection 

phase, is an experiment to evaluate diary 

formats. 

The CE Diary Survey was designed to collect 

all of the daily expenditures of sampled 

consumer units over two consecutive weeks. 

A consumer unit is defined as one of the 

following: (1) the collection of all 

members of a household who are related by 

blood, marriage, adoption, or other legal 

arrangement; (2) a person living alone or 

sharing a household with others or living 

as a roomer in a private home or lodging 

house or in a permanent living quarters in 

a hotel or motel, but who is financially 

independent; or (3) two or more persons who 

live together and pool their income to make 

joint expenditure decisions. To be 

considered financially independent, at 

least two of the three major expense 

categories (housing, food, and other living 

expenses) have to be provided by the 

respondent. 

The diary is especially effective fox 

gathering information about small, 

frequently purchased items which are 

normally difficult to recall. These 

expenditures include grocery items, meals 

eaten out, household supplies, inexpensive 

articles of clothing, and personal care 

products and services. In addition to 

expenditures, data are also collected on 

the income, work experience and demographic 

characteristics of consumer unit members. 

Each year data are collected from 

approximately five thousand consumer units 

in more than one hundred primary sampling 

units (PSU's) throughout the country. The 

sample is designed to be 

1Mathematical Statistician, Office of 

Prices and Living Conditions. 

representative of the national, 

noninstitutional population. Besides the 

population residing in regular housing, 

persons residing in selected group 

quarters, such as college dormitories, are 

also represented. Weights are assigned to 

each consumer unit in the survey in order 

to provide estimates for the U.S. 

population. 

RESPONSE ERROR IN THE DIARY 

The program of research described here is 

intended to reduce response error, in 

particular response bias. We believe that 

most response errors in the diary come in 

the form of underreports of expenditures. 

It is difficult to imagine an individual 

recording more items than were purchased or 

consistently overreporting the price of 

items, but the failure to report all items 

is quite likely given the time and effort 

required to keep the diary. There is 

substantial evidence to support this 

assertion. Sudman and Ferber [3] found that 

the estimates from consumer diaries 

recorded by hand were less than those 

obtained using taps recordings, and 

estimates of food expenditures from the CE 

diary were below those from the National 

Accounts in both the 1972-73 and 1980-81 

periods [2,6].

Response errors can contribute either to 

the bias or variance in estimates. There 

are other nonsampling errors which also can 

increase the total error in a survey and 

are not included in the sampling variance 

given in published reports. 

These errors include sampling bias, 

clerical errors and processing errors. We 

have concentrated on response error because 

we believe this form of nonsampling error 

represents the greatest threat to the 

integrity of our expenditure estimates. We 

are already using supplemental sampling 

frames, weighting and imputation to correct 

for sampling bias; and clerical and 

processing errors are more likely to be 

random than are response errors. 

APPROACH TO THE STUDY OF RESPONSE 

ERROR 

Response errors occur at the micro level 

and can be viewed as outcomes of the survey 

process. Figure 1 provides a picture of 

this process for the CE diary. The elements 

found here are similar to those found in 

other survey processes. One element which 

is not the same as in the typical survey 

situation is the respondent's 

record-keeping behavior. Usually the 

respondent's behavior is confined to 

thought processes and verbal responses. In 

the diary survey, however, the respondent 

has a more active role. 
We can see from this diagram that respondent 

(or consumer unit) characteristics, in 

combination with environmental circumstances 

and the intervening survey procedures 

(including interviewer characteristics), 

influence both the respondent's attitudes 

toward the survey and his or her 

record-keeping behavior. The attitudes and 

record-keeping behavior (both thought 

processes and physical actions) are 

collateral in that they occur at 

approximately the same point in time. 

Attitudes are thought processes, but they 

are not a part of record-keeping behavior. 

To make this point more clearly, attitudes 

are not responsible for the outcome of the 

survey process; the record-keeping behavior 

is. Obviously, in many cases, attitudes and 

recordkeeping behavior coincide; but there 

may be a number of instances where this is 

not true. 

As a first step toward the reduction of 

response error in the diary survey, we have 

to determine the causes of response errors. 

Once the causal factors are identified, we 

can develop new survey methods for 

overcoming their effects. In order to 

identify these factors, we have to 

understand how the antecedent elements in 

the survey situation interact to affect both 

attitudes and record-keeping behavior. We 

then can complete our understanding of the 

causal sequence leading to response errors 

by examining the relationships between 

particular behaviors and response errors. 

Since response errors occur at the micro 

level, we would like to carry out our 

studies at that level. To this end, we are 

engaged in research to define measures of an 

individual respondent's response error [5]; 

but we also are interested in conducting 

aggregate analyses of the expenditures 

themselves by the demographic, attitudinal 

and behavioral variables. The remainder of 

this paper discusses two research projects 

which will provide us with our first 

information about the causal sequence 

outlined above. 

THE SUPPLEMENTAL DIARY SURVEY: 

UNIVARIATE DISTRIBUTIONS 

The causal sequence leading to response 

error is extremely complicated. We have 

designed our studies to build on one another 

until we are able to analyze the survey 

process in its entirety. I have already 

mentioned the work we are doing to develop 

measures of response error. Another study 

focuses on the role of attitudes and 

record-keeping behavior. The data for this 

project came from a supplemental survey 

administered to the diary respondents and 

interviewers in the second quarter of 1984 

at the conclusion of the second diary week. 

This questionnaire, found in the appendix, 

was designed to measure the feelings and 

behaviors associated with keeping the diary. 

Some o the information also can be used to 

establish the environmental context. 

Before proceeding with a discussion of the 

supplemental survey, let me mention the 

major drawback to a survey of this 

kind--social desirability effects. Most of 

the respondents ace aware of the recommended 

method for keeping the diary. They are also 

aware of the kinds of attitudes which will 

be viewed in a favorable light. Therefore, 

there may be a tendency for respondents to 

give false answers in the socially desirable 

direction. 

With this in mind, I want to turn to a 

review of the initial findings from the 

supplemental survey, some of which are 

presented in Table 1. One of the most 

important findings is that almost twenty 

percent (215) of the respondents completed 

at least one of the diaries by total recall. 

This means that no entries had been made in 

the diary during the week so the interviewer 

had to record as many of the previous week's 

expenditures that respondent could recall. 

The extent of recall poses an obvious threat 

to the quality of the data received from the 

diary survey. The fact that so many 

respondents completed the diary by recall 

complicates our analysis because they could 

not be asked most of the questions on the 

supplemental survey. 

A potential problem with this type of survey 

is that all family members may not report 

their expenditures to the person keeping the 

diary. However, roost (848) of the CU's with 

more than one person indicated expenditures 

by members other than the record keeper were 

included; and' '` slightly more than 708 of 

these respondents said that the expenditures 

were reported daily.. Another 158 received 

reports every 2 to 3 days. Unfortunately, we 

do not know how complete the reports were. 

In order to adequately evaluate the 

respondent's reports, we asked whether the 

expenditures for the two-week diary period 

were about what the CU usually spent. Forty 

percent of the respondents said that these 

two weeks did not give an accurate 

indication of their usual expenditures. 

Almost 758 of these respondents said their 

reported expenditures were lower than usual 

while 258 said they were higher. The large 

portion falling in the "lower" category may 

indicate an attempt by some respondents to 

misrepresent underreporting. 

When we place a diary, we recommend that the 

respondent record expenditures on a daily 

basis to insure that none are forgotten. As 

a check on how closely respondents follow 

these instructions, they were asked how 

often expenditures were usually recorded. 

About 708 said they recorded expenditures 

immediately after they occurred or at the 

end of each day. Two thirds of these 

respondents said they never entered an 

expenditure after the day it occurred. As 

for those respondents reporting a delay in 
recording expenditures, the reasons most 

often given were that they forgot, they were 

busy, or they were out of town. 

When asked how they felt about keeping the 

diary, a number of respondents thought that 

the size of the diary was awkward, that the 

task required too much time and effort, 

and/or that interest in the diary declined 

over the two weeks. However, somewhat larger 

proportions felt that keeping the diary was 

enjoyable and/or beneficial. A smaller group 

of respondents found it difficult to obtain 

expenditures from other members of the CU. 

Only about a quarter of the sample had any 

suggestions for improving the diary. While 

there was a variety of these suggestions, 

the most common involved changing the diary 

format. For instance, several respondents 

felt that the weight and quantity fields 

should be eliminated. 

We also asked the interviewers to give their 

opinions of the attitudes and behaviors of 

the respondents. Almost a third of the time, 

the interviewer reported the respondent was 

reluctant to agree to keep the diary. 

According to the interviewer's opinion, 

almost a quarter of the respondents did not 

make a conscientious effort. These findings 

appear to coincide with the fact that nearly 

208 of the diaries required a recall 

interview. Impressions about the respondents

conscientiousness usually were gained from 

conscientiousness usually were gained from 

or from statements made by the respondent. 

between a respondent's attitudes toward the 

diary and his or her record-keeping 

behavior. As I pointed out then, behavior is 

what we must change in order to improve our 

estimates even though changes in attitudes 

and behavior will often. coincide. I want to 

focus now on the relationship between 

attitudes and behavior found in the 

supplemental survey. This analysis will be 

potentially very useful for differentiating 

respondents with respect to the accuracy of 

their weekly expenditure reports. 

Complicating this effort is; again, the fact 

that respondents completing the diary 

through total recall could be asked only a 

few of the questions on the survey. I will 

deal with these respondents both separately 

and in conjunction with those who did record 

expenditures in the diary. 

Because a number of items on the 

supplemental questionnaire were used to 

gather information about attitudes and 

behavior, a method was needed for 

summarizing these data so that concise 

statements about the relationship between 

attitudes and behavior could be made. Seven 

questions were chosen for use in forming an 

attitude scale. These questions are listed 

in Table 2 along with an explanation of how 

they were recoiled to create the scale. The 

five behavioral items used to develop the 

behavior scale are also listed in Table 2. 

Both respondent and interviewer reports; 

but, by and large, they are in agreement. 

The recorded values for each set of items 

were added together to produce scale values.

The higher the value on either scale, the more 

likely it is that the respondent gave an accurate 

expenditure report. 

THE SUPPLEMENTAL DIARY SURVEY: SUMMARY MEASURES

The Attitude and Behavior Scales

Earlier I spoke of the possible inconsistencies

Respondents who completed the diary by 

total recall were assigned the most 

negative value on each scale. This seemed 

entirely appropriate in the case of the 

behavior scale. As for the
attitude scale. I assumed their behavior 

indicated extremely negative attitudes toward 

the diary. We will see later, when these 

respondents are considered separately, that 

the assignment of these scale values may not 

have always been justified. 

This typology was created in the belief 

that it would differentiate respondents in 

terms of how well they reported their 

expenditures. A simple test of this 

hypothesis using information contained in 

the supplemental survey is offered in Table 

4. Remember that respondents were asked how 

their expenditures for the diary period 

compared to their usual expenditures. 

Clearly, the "accommodaters" were the ones 

most likely to report their expenditures 

were about the same as 

usual or higher. The fact that the "complainer 

said their reports were the same as usual gyre 

often than did the "resisters" and 

"misleaders" leads us to believe that, other 

than the "accommodaters, "they provided the 

most accurate expenditure reports. Again, it 

is the behavior and not the attitudes which 

determine the nature of the expenditure 

report. 

I have already stated that the assignment 

to category one of respondents who 

completed the diary through total recall 

may not always have been justified. As it 

turns out, a number of these respondents 

were elderly, so they may have been 

physically unable to keep the diary. We &o 

not know what their attitudes were or 

whether they would have kept the diary 

properly it they could have. However, an 

indication of this possibility is gained by 

examining the opinions given by the 

interviewers about the attitudes and 

behaviors of these respondents. This 

information is found in Table 5. In almost 

twenty percent of the cases, the 

interviewer said the respondent had a 

positive attitude or made a conscientious 

effort to report expenditures. While these 

data should be viewed with some skepticism 

since the interviewer's perception may be 

in error, more than forty percent of these 

respondents did say their expenditure 

reports reflected their usual expenditure. 
pictured in Figure 1. The most striking 

finding from the present analysis is that 

attitudes and behavior are often 

inconsistent, especially in the case where 

negative attitudes are associated with 

positive behavior. Again, it is-the 

respondent's behavior which we must change. 

However, in the process, we undoubtably will 

affect attitudes; and this certainly will be 

a desirable outcome. According to the 

earlier description of the survey situation, 

the same variables influence both attitudes 

and behavior. We have no control over 

consumer unit characteristics, but we can 

change the environmental context and survey 

procedures. The next section describes one 

attempt to improve survey procedures. 

THE DIARY OPERATIONAL TEST 

The Rationale 

The supplemental survey was designed to give 

initial information about the attitudes and 

record-keeping behavior of diary respondents 

and also provide some data on environmental 

characteristics. As indicated above, we can 

use this information in conjunction with 

consumer unit characteristics, other 

environmental characteristics, and 

expenditure reports to examine the survey 

process. However, this examination will be 

incomplete because we have left the survey 

procedures largely unconsidered. Since each 

respondent receives the same diary, we 

cannot know how different survey procedures 

would affect expenditure reporting. The 

purpose of another project we have recently 

undertaken, the Diary Operational Test, is 

the evaluation of the effectiveness of 

different survey procedures. 

The Design 

The effects of two variables will be 

examined in a design which uses data from 

both a special research sample and the 

regular diary sample to make comparisons. 

One variable measures the effect of the 

current practice of having the diary and the 

quarterly interview survey conducted by the 

same interviewers. Since the quarterly 

interview involves so much more of the 

interviewer's time than the diary, it is 

suspected that less emphasis has been placed 

on the quality of data gathered from the 

diary survey. To evaluate the extent to 

which this is true, two interview conditions 

have been used. In the regular sample, 

interviewers have continued to conduct both 

surveys. In the research sample, 

interviewers worked only on the diary. 

The other variable concerns the physical 

layout of the diary itself. The diary's 

format can either hinder or facilitate the 

reporting of expenditures. Recent research 

into reporting rates from both the 1972/73 

and 1980/81 diaries indicated that explicit 

references to particular products in the 

diary increases the likelihood that these 

items will be reported, especially if the 

reporting rates are low to begin with [1, 

47. To evaluate diary formats which provide 

more explicit instructions as to the 

commodities to be 

reported, two experimental diaries were 

developed. Portions of these two diaries and 

the diary currently in use can be found in 

the appendix. 

The experimental diaries have fewer 

expenditure categories than the current 

diary. They are also smaller and have mote 

attractive covers. Respondents are not 

required to specify the quantity and weight 

of items they purchase when completing the 

two experimental diaries as they must in the 

current diary. What distinguishes the two 

experimental diaries from one another is the 

specificity of the item descriptions within 

each section. In experimental diary A, only 

blank lines for recording purchases are 

provided under each of the section headings 

just like the current diary; but, in 

contrast to the latter, the section headings 

contain more complete descriptions of the 

items to be reported. Experimental diary H 

has only category titles; however, the lines 

beneath each heading have specific items 

printed on them. Respondents need only check 

whether an item was purchased and give the 

price. 

These two formats were chosen as the most 

promising alternatives for increasing the 

specificity of item descriptions. Diary A 

still gives the respondent the freedom to 

describe purchases, but it also requires a 

significant amount of writing. In the other 

experimental diary, much less writing is 

necessary; but the respondent must make 

classification choices which will take more 

thought than the blank-line condition and 

may be prone to error. Respondents roust 

also add expenditures for all items 

appearing on the same line and record the 

total. 

Table 6 depicts the features of a design 

employing the variables described above. In 

addition to the two experimental diaries, 

the current diary will be used as a control. 

These three diaries were administered at 

random to consumer units in the research 

sample, and the interviewers assigned to 

this sample did not work on the quarterly 

interview survey. The fourth cell represents 

the on-going "production" diary where 

interviewers conducted both surveys. 

Two other features of this experiment are 

worth mentioning. The first is that an 

additional section was added to the 

household characteristics questionnaire 

which is very similar to the supplemental 

questionnaire discussed previously. We hope 

to be able to distinguish between the 

attitudes and recordkeeping behavior of 

respondents exposed to the different 

experimental conditions. The other feature 

is a new method of collecting recalled 

expenditures. Currently, the interviewer 

records these expenditures directly into the 

diary using unscripted procedures and also 

asks a series of follow-up questions about 

specific commodities 
which the respondent may have forgotten to 

report (See appendix.). The new procedure, 

used with the two experimental diaries, 

involves a scripted recall section contained 

in the household characteristics 

questionnaire. One part of this recall section 

can be found in the appendix. The new recall 

section was designed to improve our ability to 

collect recall information; and, by keeping 

this data separate from expenditures recorded 

by the respondent, we will be able to 

determine the extent of recall in the diary. 

The Sample 

The sample cases for the experiment were drawn 

from 22 of our largest (self-representing) 

PSU's, and the random assignement of diaries 

to members of the research sample was carried 

out within each PSU so that approximately a 

third of the respondents in every PSU would 

receive one of the three format conditions. We 

expect about 1000 consumer units per research 

cell. These consumer units were interviewed 

between May and November of 1985. The 

production sample should have yielded about 

1300 interviews during that period in the same 

22 PSU's.