For 

Bureau of Labor Statistics 

July 17, 2012 

Don A. Dillman, Chair 

National Academies Panel on Redesign Options for 

the Consumer Expenditure (CE) Surveys 

Don A. Dillman, July 17, 2012 1 

Redesigning the BLS 

Consumer Expenditure 

Surveys; Challenges With 

Opportunities 
Purpose 

 Discuss measurement and non-response issues 

associated with the current CE Surveys. 

 The report is still in the review process; thus, I cannot 

talk about specific recommendations for redesign, but 

instead will focus on describing issues that appear to 

exist with the current CE surveys. 

 Both the interview and the diary will be part of my 

discussion, focusing first on the interview, and then the 

diary. 

Don A. Dillman, July 17, 2012 2 
The interview task is 

demanding 

 5 in-person interviews are conducted with each consumer unit 

(household) three months apart. 

 Each interview takes about 65 minutes 

 Interview #1 asks demographic information, major durable goods, 

and a one month recall of expenditures. 

 Interviews. #2-5 are quite repetitive asking respondents to report 

details of expenditures for the last three months. 

 A respondent “booklet” includes 36 pages, each with 7-70 items on 

it to help identify specific expenditures. 

 Detailed assets and changes from earlier time periods are generally 

asked in interview. #2 and #5. 

Don A. Dillman, July 17, 2012 3 
Additional aspects of 

response situation 

 Interview is usually completed with one 

person in the consumer unit who needs to 

report for all persons. 

 Records less likely to be extensively used 

(31%) than NOT used (39%). 

 Respondent has to learn rules for 

assigning dates—dates of purchase, 

delivery and payment may differ. 

Don A. Dillman, July 17, 2012 4 
Detail requested for the last 3 

months (interviews 2-5) can be 

daunting, e.g. 

 Did you purchase any “pants, jeans, or 

shorts” (in the last three months)? 

 Please describe the item 

 Was this purchased for someone inside or outside 

of your household? 

 For whom was this purchased? (Enter name, age, 

sex). 

 When did you purchase it? 

 How much did it cost? 

 Did this include sales tax? 

Don A. Dillman, July 17, 2012 5 
A difficult asset question from 

the fifth interview 

 On the last day of last month, what was the 

total balance or market value (including 

interest earned) of checking accounts, 

brokerage accounts and other similar 

accounts? 

 How does the amount your household had 

on the last day of last month compare with 

the amount your household had on the last 

day of last month one year ago? 

Don A. Dillman, July 17, 2012 6 
Two major barriers to accurate 

interview reporting 

 Knowledge and recall of expenditure 

amounts and details. 

 R may not know this information. 

 R may have known, but cannot remember. 

 Motivation to report amounts and details 

 R may be unwilling or reluctant to share what is 

known. 

 R may be unwilling to make effort to determine 

amounts and details of purchases. 

Don A. Dillman, July 17, 2012 7 
Why is knowledge and recall a 

barrier to accurate reporting? 

 Only one person likely to do the interview. 

 Records are infrequently used. 

 Even if records are used, they may not 

correspond to rules for reporting date of 

expenditure and details. 

 Purchasing and paying for products and 

services has become much more 

complicated over the last 30 years. 

Don A. Dillman, July 17, 2012 8 
Societal Changes in how consumer 

expenditures are made makes recall 

more difficult 

 Greater range of consumer expenditures. 

 Retail outlets more likely to sell unrelated items in single 

purchase (e.g. food + luggage + motor oil +socks) 

 On-line purchases are growing. 

 Multiple payment methods may be used by one 

person—cash, debit-card, credit card, and checks. 

 Automatic deductions {paycheck(s), credit card(s), bank 

account(s)} may not be registered in memory . 

 Transactions often made without cognitive attention to 

amount; the card is simply “swiped” and for smaller 

purchases no signature required. 

Don A. Dillman, July 17, 2012 9 
Societal Changes in how consumer 

expenditures are made makes recall 

more difficult(2) 

 List prices set to allow discounts on discounts. 

 Store credits and discounts sometimes applied to total 

amount of all purchases, making knowledge of purchase 

price less obvious. 

 Enormous variation in receipt structures, including 

abbreviations, makes post-knowledge of cost more 

difficult. 

 Day item obtained may not be date payment made. 

 Observation: Purchasing behavior is much more 

complex than when CE interviewing (and Diary) 

methods were developed, and these changes work 

against the recall of specific purchases and their 

cost. 

Don A. Dillman, July 17, 2012 

10
Societal changes in household 

structure add to the recall problem 

 More households have multiple wage earners. 

 Households are more likely to include unmarried 

partners. 

 Household members more likely to have expenditure 

obligations to other households (e.g. children of divorced 

parents). 

 Partners/spouses less likely to inform each other of all 

expenses. 

 Partner agreements, “I pay for food, you pay for rent,” 

may compound the knowledge problem. 

Don A. Dillman, July 17, 2012 11
Adding up the challenge 

Purchases from more sources . . . 

+ less association of product with store 

+ fewer purchases at known list price 

+ more payment streams (methods) 

+ automatic deductions for some expenditures 

+ less absorption of final price at purchase time 

+ less sharing of detail within households 

= less certainty on specific expenditures 

Don A. Dillman, July 17, 2012 12
The knowledge/recall problem 

in methodological perspective 

 One cannot report what one does not know, e.g. 

expenditures never “encoded” or partner expenditures 

not shared. 

 The interview cannot rely on establishing recall of details 

by connecting expenditures to a particular payment 

method (check book), physical location of purchase 

(shopping trip), or routine behavior of a member of the 

consumer unit. 

 Cognitive methods that could be used to enhance 

memories (e.g. calendar of events over last 3 months, or 

personalizing recall methods to individuals) are likely to 

make an already long interview more burdensome. 

Don A. Dillman, July 17, 2012 13
Motivation has multiple 

aspects 

 Belief by some that answering detailed 

expenditure and asset questions are an 

invasion of privacy or beyond the need of 

government to know. 

 The interview situation discourages obtaining 

information from other members of the 

household unless they are present. 

 Partner/teenager expenses 

 Searching for receipts and perusing records 

Don A. Dillman, July 17, 2012 14
Motivation in Methodological 

Perspective 

 Some requests for information (alcohol purchases, 

gambling costs) reduce reporting because of social 

undesirability. 

 Seeking great detail that requires significant effort to 

calculate or find , encourages satisficing: “This “number” 

is good enough”. 

 Seeking information respondent cannot easily provide 

encourages estimation.

 Estimation often results in telescoping, ie. reporting 

significant expenditures for more than three months. 

Don A. Dillman, July 17, 2012 15
Motivation in Methodological 

Perspective (2) 

 Answering “yes” to questions, e.g. Did you take an 

overnight trip or did you purchase any other clothing, 

typically leads to additional questions. 

 All five interviews can include dozens of potential 

screener questions, and respondents soon learn that a 

“no” or “not that I remember” results in fewer questions 

and a shorter interview. 

 The inability of respondents to give accurate answers 

and a belief that the answer they can give will not be 

useful, may help justify saying “no”. 

Don A. Dillman, July 17, 2012 16
Mutual interests of respondent 

and the interviewer 

 The respondent typically wants interview to 

be shorter and less work. 

 The Interviewer also wants interview to be 

shorter so the respondent will agree to 

another interview. 

 Thus, interviewers may not encourage 

respondents to look for receipts, go through 

records, divide receipts, or use other recall 

methods. 

Don A. Dillman, July 17, 2012 17
Effects of switching data 

collection to the telephone 

 38% of CE interviews are completed by 

telephone, especially the later ones. 

 Recall visual aid (the notebook)not used. 

 Telephone interviews obtain fewer “yes” 

answers to screener questions. 

 Receipts and other records are less likely to 

be used. 

Don A. Dillman, July 17, 2012 18
In summary, interview data 

quality may be negatively 

affected by... 

 Interviewing only one person in multi-person households, 

i.e. proxy reporting. 

 The long (three month) recall period. 

 Lack of knowledge respondent has for providing extreme 

detail requested. 

 Lack of motivation for making effort needed to provide 

accurate answers. 

 The repetitive nature and length of the interviews. 

 The easy avoidance of additional questions by saying 

“No, I didn’t purchase any of that.” 

Don A. Dillman, July 17, 2012 19
The Diary completion task is 

also demanding 

 Households are asked to report everything they 

purchase for two weeks.

 Week 1 diary; in-person delivery with selected 

questions and instructions. 

 Week 2 diary; in-person delivery when Week 1 

diary is picked up. 

 Interviewer returns a third time to pick up Week 

2 diary. 

 Respondent is encouraged to make diary 

entries each day purchases are made. 

Don A. Dillman, July 17, 2012 20
Learning to complete the diary 

can be confusing 

 44 numbered pages + covers + flaps = 52 surfaces of 

information 

 Respondent asked to write in names of others in 

household for whom they are reporting. 

 15 of pages provided instructions, 28 pages are laid out 

by “day” and have labeled tables for: 

 1 Food and Drinks Away From Home 

 2 Food and Drinks for Home Consumption 

 3 Clothing, Shoes, Jewelry and Accessories 

 4 All Other Products, Services and Expenses 

 Respondent asked to provide up to six pieces of 

information for each entry. 

Don A. Dillman, July 17, 2012 21
Understanding requires roundabout processing, e.g. 

 P. 9 asks for Day 1 Food and Drinks for Home. 

 Right flap of back cover provides answers to frequently 

asked questions. 

 P.3 has instructions for “How to fill out your diary” 

including request to record expenses each day. 

 P.2 has general instructions and section on what not to 

record. 

 Examples for Food and Drinks are on P. 5, e.g. specify 

white, wheat or rye bread, and instant vs. ground coffee. 

 Subsequent Daily pages for Food and Drinks are on 

Pp.13, 17, 21, 25, 29 and 33; “additional pages”. for 

overflow are Pp. 38-41

Don A. Dillman, July 17, 2012 22
Graphical navigation guidance 

is quite limited 

 All pages mix blue, gray and black positive 

and negative print; full color limited to outside 

covers. 

 Numbers are assigned to Day (1-7) as well 

as expenditure categories (1-4) and pages 

(1-44), so may not be an effective guide. 

 If diary is not filled out each day expenses 

are made, flipping of non continuous pages is 

required. 

Don A. Dillman, July 17, 2012 23
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Don A. Dillman, July 17, 2012 26
Knowledge as a barrier to 

Completing the Diaries 

 In principle less of a problem unless 

 Respondent doesn’t ask other unit members for 

expenses. 

 Receipts not kept for some purchases. 

 Receipts make it difficult to identify items 

(abbreviations) 

 Knowing and applying rules may produce inaccurate 

recordings that are difficult to catch. 

 Information may not be available in a timely way, e.g. 

auto deductions from bank account. 

 Society changes (see interview discussion) also apply 

here. 

Don A. Dillman, July 17, 2012 27
Motivation as a barrier 

 Recording requested detail on daily basis 

may be seen as a considerable burden. 

 Long itemized receipts may be difficult to 

enter, e.g. if discount applied to an entire bill 

and abbreviations used. 

 Abbreviations may be impossible to interpret. 

 Respondents may delay shopping trip to 

avoid the “need” to record. 

Don A. Dillman, July 17, 2012 28
In Sum, Diary responses are 

negatively affected by... 

 ...both knowledge (e.g. proxy reporting) and 

motivation. 

 In addition, design and layout procedures 

present problems—some respondents decide 

only to collect receipts because of how 

difficult the task seems to be. 

 An outcome. Some diaries (especially second 

week) do not get completed. 

Don A. Dillman, July 17, 2012 29
Is one of these modes (interview vs. 

diary) fundamentally better than the 

other? 

 A difficult question to answer. 

 The original goal was to collect different kinds of information—big 

and recurring expenses from interview and small detailed ones from 

diary. 

 Each now ask some of the same topics, but in different ways, e.g. 

food for home consumption. 

 Interview- “What has been your or your household usual 

WEEKLY expense for grocery shopping?” 

 Diary—A listing of each item that asks, e.g. white vs. wheat 

bread, types of meat, and if purchase was for someone else. 

 These are quite different questions, subject to different 

kinds of errors associated with “estimation” vs. “reporting 

of details”. 

Don A. Dillman, July 17, 2012 30
A cognitive perspective on the 

search for improved accuracy 

 Typical approaches to getting better 

measurement include: 

 Ask more detailed questions. 

 Create a memory context, e.g. daily activities and 

event history of last three months. 

 Personalize questions to how people are most 

likely to recall expenditures. 

 Observation: Would these kind of efforts 

make a demanding survey interview/diary 

even longer and more demanding? 

Don A. Dillman, July 17, 2012 31
A related question: Is the 

extreme detail necessary? 

 The CE surveys serve multiple purposes: 

 CPI Index 

 Administration of government programs 

 Policy analyses 

 Are less detailed estimation questions 

adequate for some of these purposes, but not 

others? 

 Is the extreme detail necessary for any of 

these purposes (e.g. white vs. wheat bread)? 

Don A. Dillman, July 17, 2012 32
Conclusion 

 The issues described today are only some of 

the issues that have been under discussion. 

 The Panel report is still under review, and 

should be finished soon. 

 Recommendations will be in the report 

 Meantime we would welcome your questions 

and comments. 

Don A. Dillman, July 17, 2012 33