RESEARCH POSTER PRESENTATION DESIGN © 2012

www.PosterPresentations.com

The CEQ is an in-person survey that collects all expenditures a 

household incurs over a prior 3-month period (a small proportion of 

cases are interviewed by telephone). Starting in 2015, the Consumer 

Expenditure (CE) Survey staggered introduction of the CEQ that did 

not include the first bounding wave, shifting questions from that wave 

onto the new first wave. This allowed us to compare households 

answering questions after having completed a prior interview to bound 

their reports (‘Old Wave (OW)’) with households in the same month 

getting the same question content but without a prior interview to 

bound their reports (‘New Wave (NW)’). 

First, we examined two sets of expenditure categories: 

large/irregularly-purchased items (e.g., furniture, major appliances) 

more vulnerable to have reports ‘telescoped’ into the reference 

period, and smaller/regularly-purchased items (e.g., health care, 

small appliances) less vulnerable to telescoping errors*. 

A second comparison involved the average length of the interview 

waves. The length of November 2015 interviews were compared to 

interviews involving the same content, but fewer questions, one year 

earlier.

Relatedly, we examined whether the change in interview length 

affected later non-response rates. We calculated the change in nonresponse between the first (unbounded, longer) wave and the second 

wave in the first half of 2015, contrasted with that same change in the 

prior year when the initial wave was shorter.

BACKGROUND 1. Increases in Expenditure Reporting

The Consumer Expenditure Interview Survey (CEQ) moved from a fivewave panel design to a four-wave design in 2015, eliminating the 

interview used to ‘bound’ a household’s expenditure reports. This 

poster shows how three aspects of the CEQ changed following 

introduction of the new design:

1. the proportion of respondents reporting having an expenditure by 

expenditure category

2. the interview length, and 

3. the subsequent wave non-response rates.

Findings about the design change can guide decisions regarding the 

utility of having bounding interviews in multi-wave surveys and inform 

how changes in interview length may affect subsequent wave nonresponse.

METHODS

Hypothesis 2: Average interview lengths for the new first interview 

will increase from adding questions from the old bounding interview.

Interview waves were compared with their equivalent waves before 

elimination of the bounding interview to identify the change in 

duration that resulted. 

The results indicated that new initial interviews, having added 

questions from the prior wave 1 interview, were an average of 17.1 

minutes longer than corresponding wave 2 interviews a year prior. 

Duration increases were small or non-existent for subsequent wave 

interviews. There was a 12 percent overall reduction in interview time 

across waves due to the move from 5 to 4 waves.

The increases above (using November data) were smaller than they 

were for the year-over-year comparison in May, when new wave 2 

interviews took over 20 minutes longer than old wave 1 interviews. 

Note that the compared interviews were completed primarily inperson.

2. Increased Interview Length CONCLUSIONS

Moving from a five-wave design to a four wave-design in 2015 was 

associated with changes in both reporting frequencies and the length 

of interview components, but not associated with changes in nonresponse patterns. 

The findings related to our hypotheses were:

1) Increase in proportion of households reporting large expenditures 

– furniture, major appliances – in the unbound interviews

a) This was despite households in the unbound sample having 

lower income levels than those in the other sample

b) There were geographic differences between the samples –

more rural households in the bound sample; Removing those 

households led the increase in reporting for major appliances 

to no longer be significant, while the increase in reporting 

furniture expenditures remained significant

2) An average increase in the duration of the initial interview of over 

17 minutes (offset by an overall decrease across all waves of 35 

minutes)

a) Consistent with the addition of new questions (e.g., 

identifying households’ housing, vehicle and medical 

attributes)

b) The increase was reduced after the interviewers had a period 

of time to become familiar with the new interview structure

c) Due to the removal of the bounding interview, overall 

interviewing time was reduced from 285 minutes to under 

250 minutes

3) An increase in refusal between the first and second interview 

waves, but not a significantly larger increase than what was 

observed a year prior (consistent with general increases in survey 

non-response)

These findings suggest, but do not prove, the presence of telescoping 

errors. These errors appear in certain expenditure categories when 

there is no longer a bounding interview to flag expenses that fall 

outside of the reference period. These findings also suggest that 

adding questions to an interview, while adding time, may not 

automatically lead to greater attrition when households are contacted 

3 months later for a subsequent interview.

Hypothesis 1: A larger proportion of households will report large 

expenditures in the NW compared to the OW group (consistent with 

telescoping errors in new unbounded interviews).

The comparison of reporting frequency between the sample without a 

bounding interview (NW) and those with data to bound their interview 

(OW), both in April of 2015, is displayed below.

Tests* of the differences indicate significant differences for Furniture 

(increase), Major Appliances (increase), and Clothing (decrease).

Two characteristics of the samples may have affected the proportion 

reporting expenditures – income, and rural/urban geography. 

Income: The bound (OW) sample had significantly higher income levels 

(median family income $52,757) than the unbound (NW) sample 

(median family income $38,000) (Z=-5.27 p<0.0001). 

Geography: The bound (OW) sample was less like to be comprised of 

rural households (8.0%) than the unbound (NW) sample (35.7%) 

(Z=737, p<0.0001).

Controlling for the geographic differences, Furniture remained 

significant, while Major Appliances and Clothing were no longer 

significant (Health Care and Utilities now showed significant 

decreases). 

*Wilcoxon-Mann-Whitney two-sided tests

Hypothesis 3: In 2015, after bounding elimination, there will be 

higher rates of non-response at the second wave due to respondents 

having longer first wave interviews.

The change in non-response (first to second wave) was compared 

between 2014 (in green) and January-June 2015 (in purple), each with 

the following first wave characteristics:

• 2014: bounding interview, shorter 

• 2015: no bounding, with additional questions, and longer

* Indicates significant change (Chi-Sq p<0.01)

Non-contact

The second wave had non-significantly lower rates of non-contact than 

in the first wave in 2015 (-0.1%, in purple) but the difference from 

2014 to 2015 was not significant (Breslow-Day 0.9025). 

Refusal

There was a significant increase in refusals going from the first wave 

to the second wave in 2014, prior to the longer first wave (2.9%, in 

green). The increase in refusals was also significant in 2015 (3.4%, in 

purple), but the increase was not significantly higher than in the prior 

year (Breslow-Day 0.9213). 

Non-Response

Overall non-response (with its non-contact and refusal components) 

exhibited the same changes as refusal – increasing, but not increasing 

significantly more after the first interview became longer.

3. Similar Non-Response Patterns

Brett McBride, John Dixon

U.S. Bureau of Labor Statistics

Evaluating the Impact of Eliminating a Bounding Interview

*

*

-10% *

0%

10%

20%

30%

40%

50%

Furniture

(N=203)

TV/Radio

(N=1,379)

Major

Appliances

(N=149)

Clothing

(N=1,193)

Small

Appliances

(N=228)

Health care

(N=1,353)

Utilities

(N=1,641)

Percent Change in Proportion of CUs Reporting 

Expenditures, by Category 

(Red = Unbound > Bound)

Prop. Bound 

(OW)

Prop. Unbound 

(NW) % Difference Wilcoxon Z Prob. > Z 

Furniture 0.108 0.141 30.4% 2.01 0.045

TV/Radio 0.816 0.822 0.6% 0.27 0.790

Major Appliances 0.076 0.110 45.0% 2.39 0.017

Clothing 0.728 0.674 -7.4% -2.36 0.018

Small Appliances 0.131 0.142 8.7% 0.67 0.506

Health Care 0.813 0.787 -3.1% -1.27 0.203

Utilities 0.979 0.966 -1.4% -1.67 0.094

Old name 

(new) N Mean N Mean

Net 

Difference % Difference

Wave 1 (NA) 560 56.6

Wave 2 (1) 574 62.4 522 79.5 17.1 27.4%

Wave 3 (2) 529 54.8 540 55.9 1.1 2.0%

Wave 4 (3) 550 53.1 543 53.1 0.0 0.0%

Wave 5 (4) 539 58.1 200 61.3 3.2 5.5%

2014 2015

Change in mean duration (in minutes) by interview wave

*

*

* *

-1.0%

-0.5%

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

4.0%

Non-Contact Refusal Overall Non-Response

Percentage point change 

Change in Non-Response by Type 

(positive % change = wave 2 non-response > wave 1)

2014 (Shorter) 2nd-1st 2015 (Longer) 2nd-1st

Brett McBride

DIVISION OF CONSUMER EXPENDITURE SURVEY

U.S. BUREAU OF LABOR STATISTICS bls.gov

mcbride.brett@bls.gov

*Telescoping error occurs when an event (or expenditure) is 

temporally misreported as occurring in a time period 

different from when it actually occurred. This is thought to 

mainly effect large events which are salient in respondents’ 

memories and thus are not forgotten but instead are 

reported in a later time period (‘forward telescoping’).

2014 

(2nd-1st)

2015 

(2nd-1st)

Non-Contact -0.4% -0.1%

Refusal 2.9%* 3.4%*

Overall Non-Response 2.5%* 3.3%*