Measuring School Enrollment in the 2011 SIPP-EHC Field Test 

Stephanie Ewert and Sarah Crissey 

U.S. Census Bureau 

Social, Economic, and Housing Statistics Division 

Presented at the Federal Committee on Statistical Methodology Research Conference 

Washington, DC 

January 11, 2012 

SEHSD Working Paper # 2012-4 

This report is released to inform interested parties of research and to encourage discussion. The views expressed on 

statistical and technical issues are those of the authors and not necessarily those of the U.S. Census Bureau. 
1 

Introduction 

Since it’s inception in 1984, the main objective of the Survey of Income and Program Participation (SIPP) has been 

to provide accurate and comprehensive sub-annual information about the income and program participation

dynamics for individuals and households in the United States. In addition to economic and program participation 

information, the SIPP also tracks a variety of topics over time, such as marital status, employment, and school 

enrollment. The school enrollment topic is unique to other topics in SIPP because of expected changes due to 

summer breaks and grade level changes. 

The most recent SIPP panel started in 2008, and has been interviewing sampled households every 4 months to 

collect monthly data. The U.S. Census Bureau is re-engineering the SIPP to accomplish several goals, including 

reducing burden on respondents, reducing program costs, improving accuracy, improving timeliness and 

accessibility, and improving relevance. A key component of the re-engineering process is shifting from the current 

every-four-month data collection schedule of traditional SIPP to an annual data collection in the re-engineered 

survey (SIPP-EHC). In order to collect monthly data over a longer time period, the SIPP-EHC uses event history 

calendar (EHC) methods (Fields and Callegaro, 2007). The EHC is a survey methodology that has been 

successfully employed since the 1960’s to assist interviewers in collecting detailed data with long recall periods 

(Belli, 1998; Belli, Shay, and Stafford, 2001). The U.S. Census Bureau is re-engineering the SIPP to incorporate 

EHC methods. 

This paper evaluates how well SIPP-EHC captures school enrollment data by comparing estimates of school 

enrollment collected via the SIPP conventional questionnaire and the event history calendar in SIPP-EHC. The 

paper further examines how SIPP and SIPP-EHC estimates align with enrollment estimates from other national 

surveys including the American Community Survey (ACS) and Current Population Survey (CPS). Evaluating the 

effectiveness of the SIPP-EHC in capturing enrollment data is particularly useful given the uniqueness of the school 

enrollment topic. 

Background 

EHC Techniques 

A primary concern associated with the shift to annual interviewing and the continued emphasis on the collection of 

monthly data is the potential for degradation in the quality of monthly reporting due to recall errors. Belli (1998) 

provides a strong theoretical rationale for the use of EHC methods, and their likely superiority to more traditional 

survey instruments using a standard question-by-question approach in a conventional questionnaire. When 

compared to conventional questionnaire (CQ) methods in randomized design studies, EHCs have shown better data 

quality for retrospective reports in terms of precision of the placement of events in time, and in terms of reducing 

underreporting. Belli, Shay, and Stafford (2001) studied Panel Study of Income Dynamics respondents randomly 

assigned to EHC or conventional conditions using validation data collected from the same respondents (PSID) years 

before. They showed that EHC reports were more precise (less underreporting, higher agreement between reports) 

than reports from the conventional questionnaire on number of moves, income, weeks unemployed, and weeks 

missing work resulting from personal illness, the illness of another, or the combination of the two. 

Most existing EHC evaluations are consistent with the hypothesis of improved data quality – acting through 

improvements in the ability of respondents to integrate memory across topic areas and retrieve related information in 

a more natural autobiographical manner. The research base of strong quantitative evaluations of theory-based 

predictions of EHC behavior is somewhat limited. Most studies have focused on the use of comparable survey 

recall periods and evaluated strictly the survey method. Thus, concern lingers about the data quality implications for 

the topics covered in SIPP with the shift from a four-month recall period to a one-year or longer recall period. This 

paper documents the work accomplished to this point and the findings related to recall and survey design decisions 

in the development of the SIPP-EHC instrument. 

Although never implemented as a production instrument at the Census Bureau, the Census Bureau and SIPP 

researchers have experience with EHC instruments. In the late 1980’s an EHC was field tested with SIPP in the 

Chicago region (Kominski, 1990). In the end this test was not implemented as a production component because 

there were too many concomitant changes required to integrate it into the program. Similar to an event history 
2 

calendar, a ‘Residential History Calendar’ was implemented as part of the Survey of Program Dynamics, a special 

follow-on study to the 1992 and 1993 panels of SIPP. In the late 1990’s, the development of EHC instruments as 

electronic instruments began, significantly easing some of the issues associated with retrieving and coding the data 

collected with this tool. The EHC methodology helps interviewers and respondents by allowing recall of

information in a more natural “autobiographical” manner. The respondent cues their memories off of landmark 

events they can clearly place in time during the reference period, as well as from answers to other domains in the 

EHC. We outline the basic information surrounding the decision to pursue an EHC in the re-engineered SIPP as 

well as some background on the history EHC instruments in Fields and Callegaro (2007).

Differences in School Enrollment Data Collection between SIPP and SIPP-EHC 

The SIPP 2008 Panel collects monthly school enrollment data for adults age 15 and over, including information 

about grade of enrollment, type of school (public versus private), and enrollment status (full- versus part-time). The 

SIPP 2008 Panel collects information about children’s schooling bi-annually as part of a Child Well-Being topical 

module and the Child Care topical module, but these are not monthly school enrollment data. The SIPP-EHC 

enrollment content, including grade, type of school and enrollment status, was selected in part through suggestions 

from stakeholders about important content to retain. Stakeholders expressed interest in collecting information about 

school enrollment for children, particularly outcomes such as grade repetition and head start enrollment. We decided 

to expand the universe for school enrollment to everyone age 3 and over so that users would have monthly data 

about children as well as adults. 

We made several modifications to the existing SIPP 2008 items in order to accommodate a wider age universe. The 

grade level categories in SIPP 2008 were collapsed for elementary and high school, so we expanded the response 

categories to include single year of enrollment for grades 1-12. We also included new categories for nursery school 

and kindergarten. Research from the American Community Survey (Crissey, Bauman, and Peterson, 2007) showed 

that respondents with home schooled children experienced difficulty selecting public or private school type, so we 

included a third response category for home schooling. The 2008 SIPP asks anyone enrolled in school whether they 

are enrolled full time or part time, but the SIPP-EHC excluded anyone enrolled in grades 1-12 from the universe. 

Both the 2008 SIPP and the SIPP-EHC include an item about whether a child had ever repeated a grade. With the 

monthly SIPP-EHC data on grade of enrollment, it is also possible to collect information about whether a child had 

repeated a grade during the reference year. We included an item that asked about grade repetition or retention for 

respondents in grades 1-12 who reported being enrolled in the same grade at the beginning and end of the reference 

year. 

SIPP-EHC Field Testing and Instrument Changes 

The first field test of the SIPP-EHC was based on a paper version of the EHC. Respondents from the 2004 SIPP 

Panel were re-contacted to complete an abbreviated version of the EHC that collected limited information about 

program participation, employment, health insurance, and school enrollment during the same time period. Responses 

to the 2004 SIPP items were compared to the EHC responses to assess differences in enrollment rates over the 

course of a calendar year. Analyses revealed no difference in enrollment rates in the later months of the year 

(August-December), but the estimate from the EHC was higher in summer months and the SIPP estimate was higher 

in the beginning of the year (Moore et al., 2009). 

One explanation for domains where EHC estimates were lower than SIPP estimates early in the calendar year is that 

people are likely to have memory decay and so have difficulty remembering events further in the past. There is some 

evidence of this with the school enrollment 2008 Field Test Data, perhaps suggesting that respondents had forgotten 

about school enrollment early in the year. However, there are also periods where the estimates from the EHC exceed 

those from the SIPP. Notably, these are all summer months. Unlike other domains captured in the EHC, school 

enrollment has seasonal variation based on school calendar. Even people who are “continually” enrolled in school 

have a break in attendance, most frequently over the summer months. Field observations revealed that respondents 

reported being enrolled all year and underreported breaks in school enrollment over the summer. 

The second field test of the SIPP-EHC, collected in 2010, was a Computer Assisted Personal Interview (CAPI) 

using an automated instrument. In response to the 2008 field test data that showed higher than expected enrollment 

during the summer months, we included an instrument check for when respondents provided a spell of enrollment 
3 

that covered the entire year. We instructed Field Representatives to divide spells based on breaks in attendance or 

changes in grade level. 

The third field test was an updated CAPI instrument collected in 2011. Among the improvements added to all 

domains were modified introductory questions as well as a follow-up for each section to confirm that respondents 

did not have any additional periods of data to report. In the 2010 SIPP-EHC, there was a single introductory 

question for the enrollment section that asked whether respondents were enrolled at any time during the calendar 

year. In 2011, respondents were first asked if they were currently enrolled. If not, respondents were then asked if 

they had been enrolled at any time since the beginning of the calendar year. Prompting respondents with two 

separate questions should help improve memory recall of events earlier in the calendar year. 

Research Questions 

This paper evaluates the quality of the school enrollment data captured in the 2011 SIPP-EHC by answering the 

following research questions: 

1. How do 2008 SIPP Panel and 2011 SIPP-EHC Field Test data compare to national estimates of school 

enrollment from the ACS and CPS across key characteristics including age and grade level of enrollment?

2. How well does the 2011 SIPP-EHC Field Test Data compare to the 2008 SIPP Panel data in terms of 

monthly enrollment rates for the 2010 calendar year? 

Data and Methods 

Data 

We used data from the 2008 SIPP Panel, the 2010 SIPP-EHC Field Test, the 2011 SIPP-EHC Field Test, the 2010 

ACS, and the 2010 CPS. The 2008 SIPP Panel is a nationally representative longitudinal survey of the U.S. that 

began in 2008 with follow-up interviews every four months. We used data collected in Waves 5-8 in order to 

capture all of the data from the 2010 calendar year needed to calculate monthly enrollment rates. 

The 2011 SIPP-EHC oversampled high poverty strata and was geographically matched to the SIPP 2008 Panel. The 

SIPP-EHC 2011 sample covers about 20 states and includes approximately 7,000 people. Therefore, SIPP-EHC 

estimates are not nationally representative. Consequently, in this paper we examine 2008 SIPP estimates based on 

the entire sample as well as a subset of the 2008 SIPP panel that is geographically matched to the SIPP-EHC 2011 

sample (subsequently referred to as the geo-matched SIPP data). 

The key differences in enrollment content between 2008 SIPP Panel and the 2011 SIPP-EHC field test 

questionnaires were outlined above, but here we highlight key differences again. SIPP-EHC collected monthly 

enrollment with detailed grade level for everyone age 3 and over, while the 2008 SIPP panel only gathered broad 

level of enrollment for the population age 15 and over. Since SIPP-EHC gathers enrollment information for an 

entire calendar year, the questionnaire also includes an item about grade repetition for respondents enrolled in the 

same grade at the beginning and end of the year. Although the 2008 SIPP panel asked whether a child had ever 

repeated a grade, the SIPP-EHC data documents which respondents repeated a grade during the reference year and 

which grade respondents repeated. Both of these surveys include people enrolled in vocational certificate programs. 

The CPS survey samples approximately 72,000 housing units each month. The school enrollment data come from a 

special supplement administered each October. The supplement asks detailed questions of everyone age 3 and over 

regarding enrollment status, level of enrollment, and whether the respondent attended school full-time or part time. 

The ACS data come from a sample of about 3 million addresses. The ACS survey asks respondents throughout the 

calendar year whether they were enrolled in regular school at any point in the three months before the interview. 

The survey asks about enrollment during the last three months in order to capture school enrollment of respondents 

who were interviewed during the summer months when they were not currently attending school. The ACS also 

asks about whether each individual attended public or private school and the grade or level of enrollment. 

Methods
4 

We first create person-month files for the 2010 calendar year for the 2008 SIPP Panel and the SIPP-EHC 2011 

panel. 

We then begin by comparing SIPP and SIPP-EHC data to ACS and CPS to examine whether SIPP and SIPP-EHC 

estimates of enrollment by selected characteristics are reasonable given differences in sample between them and the 

ACS and CPS. We first compare enrollment estimates by age for October 2010 in SIPP and CPS to determine 

whether the national estimates align. Here we restrict the sample to adults. We then compare enrollment rates by 

age between SIPP-EHC and the geo-matched SIPP. 

After exploring how well SIPP and SIPP-EHC capture enrollment by age, we then focus on estimates of enrollment 

by grade level. Since ACS, CPS, and SIPP-EHC all collect level of enrollment in more fine-tuned categories and for 

a greater age range than SIPP, we focus on these surveys and compare the percentage of enrolled people by grade 

level. In order to capture the full distribution of enrollment level, we include all people who are enrolled who are 

age three and over. 

After determining whether SIPP and SIPP-EHC enrollment estimates are reasonable compared to other national 

estimates, we then turn to a comparison between SIPP and SIPP-EHC to evaluate the effectiveness of the SIPP-EHC 

in capturing school enrollment. We weight the geo-matched SIPP data with the SIPP 2008 final person weights 

from January 2010 and the SIPP-EHC data with preliminary weights that weight the data up to the geo-matched 

SIPP. We compare monthly enrollment rates for the calendar year 2010 between SIPP-EHC and the geographically 

matched SIPP. In order to evaluate changes between the 2010 and 2011 SIPP-EHC Field Tests, we also briefly 

show monthly enrollment rates for calendar year 2009 from SIPP-EHC. 

We then utilize the strength of SIPP-EHC data and examine enrollment rates for children, data that was unavailable 

in the 2008 and earlier SIPP Panels. We briefly compare enrollment rates by age for young children from CPS and 

SIPP-EHC to check whether SIPP-EHC captures reasonable estimates for the enrollment of children. Although 

SIPP-EHC is an over sample of low income areas, this should be less of an issue for young ages when school 

attendance is mandatory nationwide. 

Lastly, we very briefly examine the SIPP-EHC data on grade repetition but do not focus on these analyses due to the 

very small sample size. 

Results

Table 1 compares enrollment rates by age for adults in October 2010 in CPS and 2008 SIPP. Differences in 

enrollment rates by age group between the two surveys ranged from 1.3 to 4.8 percentage points. There were higher 

enrollment rates in CPS than SIPP for adults age 15 to 17 and lower enrollment rates in CPS than SIPP for adults 

age 20 to 34 and 55 and over. There were no significant differences in enrollment rates for adults age 18 to 19 and 

35 to 54. These results show that 2008 SIPP does a reasonable job of capturing school enrollment across age groups 

for adults given differences in survey design between CPS and SIPP. 

Table 2 compares enrollment rates by age in October 2010 in SIPP-EHC and geo-matched 2008 SIPP. Both surveys 

show lower enrollment rates among older ages than among younger ages. The low enrollment rates during the

teenage years might reflect the fact that both the SIPP-EHC and geo-matched SIPP data draw from 

disproportionately low income communities where teenagers have relatively high rates of high school dropout and 

relatively low rates of college enrollment. Estimated enrollment rates in geo-matched SIPP and SIPP-EHC were not 

different for most age groups. The only significant difference in enrollment rates was found among adults aged 35 

to 44. Among this age group, 4.6 percent of adults in geo-matched SIPP were enrolled compared to 8.3 percent in 

SIPP-EHC. While Table 1 illustrated that 2008 SIPP produced enrollment rates by age that are not different from 

CPS, Table 2 show that SIPP-EHC produces enrollment rates by age that are not different from geo-matched SIPP. 

After exploring how SIPP and SIPP-EHC capture enrollment by age, Table 3 compares enrollment rates by level of 

school enrolled for ACS, CPS, and SIPP-EHC in calendar year 2010. It is important to remember that the surveys 

measure enrollment differently and so the estimates from ACS represent the average for the year while the estimates 

for CPS and SIPP-EHC represent the grade distribution of enrollment in October of 2010. The distribution of grade 
5 

of enrollment does not significantly differ between ACS and SIPP-EHC. There are no significant differences in the 

percentages enrolled in nursery school, high school, and undergraduate college years in CPS and SIPP-EHC. A 

higher percentage of enrolled students are in nursery school and graduate or professional school in CPS than SIPPEHC while a lower percentage are in grades 1 through 8. All three surveys show that between one-fifth and onequarter of enrolled students are in each of the following grade ranges: 1-4, 5-8, 9-12, and undergraduate college. 

We next turn to a comparison of monthly enrollment rates for adults in calendar year 2010 between geo-matched 

SIPP and SIPP-EHC. Overall, Table 4 shows that monthly enrollment rates between the two surveys do not differ. 

Monthly enrollment rates in 2010 do not differ between the two surveys except in February, July, and August. The 

geo-matched SIPP enrollment rates are higher than SIPP-EHC during the summer months of July and August. 

Summer enrollment is expected to be particularly low for adults given the typical academic calendar of 

undergraduate and graduate school programs, and so this finding suggests that SIPP-EHC may be capturing adult 

enrollment well during the summer. The first field test of the EHC showed higher enrollment rates during the 

summer months than in the 2004 SIPP panel, raising concerns that the EHC was not initially capturing attendance 

breaks (Moore et al., 2009). That the SIPP-EHC 2011 data now show lower summer enrollment rates suggests that 

the added instrument check for long spells, which asks Field Representatives to confirm that there are no breaks in 

attendance for reported long spells, is effectively capturing breaks in enrollment during the summer months. SIPPEHC enrollment rates at the beginning of the year are not different from those at the end of the year. 

Figure 1 displays monthly enrollment rates for geo-matched SIPP and for SIPP-EHC 2011 (calendar year 2010) and 

SIPP-EHC 2010 (calendar year 2009). The overlapping monthly enrollment rates from SIPP-EHC 2011 and SIPPEHC 2010 suggest that the EHC format is producing reliable enrollment estimates. 

One critical way SIPP-EHC was expanded from the 2008 SIPP Panel was in collecting enrollment information for 

children in addition to adults. The 2008 SIPP Panel only collected information from adults age 15 and over while 

SIPP-EHC collected information from respondents age 3 and over. Monthly enrollment data for children will be 

critical for stakeholders interested in child well-being and child outcomes. Although CPS and SIPP-EHC do not 

represent similar populations, Table 5 compares October 2010 enrollment rates for children age 3-17 from CPS and 

SIPP-EHC to see whether SIPP-EHC estimates are reasonable compared to national estimates. The estimates differ 

for ages 3-4 (when attendance is not mandatory) and for ages 14-17 as some young adults face higher risk of 

dropout than others. The estimates also differ for ages 5-6. These differences likely reflect the fact that SIPP-EHC 

respondents are disproportionately drawn from low-income populations where young children are less likely to be 

enrolled in formal nursery school or pre-Kindergarten programs, and young adults are more likely to drop out of 

high school than children from more advantaged backgrounds. Also, the CPS sample includes people throughout 

the nation while the SIPP-EHC 2011 sample only includes about 20 states. Estimated enrollment rates do not differ 

in CPS and SIPP-EHC for children age 7 to 13. 

The SIPP-EHC data will also be useful to stakeholders interested in child outcomes because of the yearly 

information on grade repetition. However, due to the SIPP-EHC sample size and the low rates of grade repetition, 

we do not include analyses of grade repetition in this paper. 

Conclusions 

This paper evaluated the quality of the school enrollment data from the SIPP-EHC instrument. We compared

enrollment rates to those from the 2008 SIPP Panel, ACS, and CPS, and examined rates by age and grade level of 

enrollment. Overall, these analyses show that the school enrollment data from the SIPP-EHC instrument look

reasonable. It is remarkable that different methods of data collection (EHC versus conventional questionnaires) with 

different reference periods (one month, four months, one year) from four different surveys produce some estimates 

that do not differ. 

It is critical to closely examine the school enrollment data while evaluating the effectiveness of the SIPP-EHC 

instrument given the unique aspects of the enrollment topic. Unlike other topics in the EHC, we expect to see 

changes in school enrollment over the course of the reference year due to summer breaks and grade level changes. 

Low rates of enrollment during the summer months and enrollment rates that are not different during the beginning 

and end of the year provide evidence that the SIPP-EHC reasonably captures school enrollment. Improvements 

made to the instrument, including a check for long spells of enrollment, seem to have been effective. 
6 

The SIPP-EHC will be a valuable source of school enrollment data as it collects monthly enrollment data for 

children and adults in a longitudinal study with rich information on other relevant topics such as migration, 

employment, and marital status. 
7 

References 

Belli, Robert F. 1998. “The structure of autobiographical memory and the event history calendar: Potential 

improvements in the quality of retrospective reports.” Memory, 6: 383-406. 

Belli, Robert F., William L. Shay, and Frank P. Stafford. 2001. “Event History Calendars and Question List 

Surveys: A Direct Comparison of Interviewing Methods” Public Opinion Quarterly, 65(1): 45-74.

Crissey, Sarah, Kurt Bauman, and Alan Peterson. 2007. “Evaluation Report Covering 

School Enrollment.” 2006 American Community Survey Content Test Report, 

P.2.a. U.S. Census Bureau. 

Fields, Jason and Mario Callegaro. 2007. “ Background and Planning for Incorporating an Event 

 History Calendar into the Re-Engineered SIPP.” Presented at the Federal Committee on 

 Statistical Methodology Research Conference, November 5-7, 2007, Arlington, Virginia. 

Kominski, Robert. 1990. The SIPP Event History Calendar: Aiding respondents in the dating of 

 longitudinal events. In Proceedings of the Section of Survey Research Methods (pp. 553- 

 558). Washington D.C.: American Statistical Association.

Moore, Jeff, Jason Fields, Joanne Pascale, Gary Benedetto, Martha Stinson, and Anna Chan. 

2009. “A Comparison of Survey Reports Obtained via Standard Questionnaire and Event History 

Calendar.” Presented at the American Association for Public Opinion Research Annual Meeting, May 14-

17, Hollywood, Florida. 
Table 1. Enrollment Status of the Population 15 Years and Over: October 2010 

 

 

 

 

Comparison of CPS, SIPP 2008, Estimates 

(Total population numbers in thousands. Civilian noninstitutionalized population) 

Total Population % Enrolled Difference 

CPS SIPP CPS SIPP CPS-SIPP 

AGE 

.15 years old 3,983 4,078 

 

 

98.6 93.8 4.8 * 

.16 and 17 years old 8290 8,365 96.1 93.6 2.5 * 

.18 and 19 years old 8529 8,666 69.2 70.5 -1.3

.20 and 21 years old 8681 8,691 52.4 56.0 -3.6 * 

.22 to 24 years old 12449 12,229 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

28.9 33.7 -4.8 * 

.25 to 29 years old 21117 21,201 14.6 16.1 -1.5 * 

.30 to 34 years old 19981 19,898 8.3 9.6 -1.3 * 

.35 to 44 years old 39980 39,980 4.7 5.0 -0.3

.45 to 54 years old 44331 44,331 2.5 2.7 -0.2

.55 years old and over 75173 75,172 0.5 0.7 -0.2 * 

*Significant difference at the .05 level. 

Source: U.S. Census Bureau, 2010 Current Population Survey, Survey of Income and Program 

Participation, 2008 Panel, Waves 5-8. For information on sampling and nonsampling error see 

<www.census.gov/sipp/source.html>.

Table 2. Enrollment Status of the Population 15 Years Old and Over: October 2010 

Comparison of SIPP 2008 Panel and 2011 SIPP-EHC Estimates 

Weighted N (in thousands) % Enrolled Difference 

SIPP SIPP SIPP- geo SIPPgeo match SIPP-EHC geo match EHC SIPP-EHC 

AGE 

 15 years old 389 391 94.61 94.5 0.15

 16 and 17 years old 788 806 92.32 92.1 0.25

 18 and 19 years old 800 850 67.42 57.1 10.36 

 20 and 21 years old 836 966 47.97 42.2 5.80

 22 to 24 years old 1,208 1,394 35.01 35.0 -0.03

 25 to 29 years old 2,000 2,233 12.97 16.6 -3.63

 30 to 34 years old 1,797 1,795 8.49 8.8 -0.35

 35 to 44 years old 3,222 3,571 4.60 8.3 -3.74 * 

 45 to 54 years old 3,397 3,389 2.91 3.0 -0.11

 55 years old and over 4,944 5,206 0.67 1.1 -0.42

Note: SIPP geo match file is a sub sample of SIPP geographically matched to 2011 SIPP-EHC. SIPPEHC weighted to geo-matched SIPP. 

*Significant difference at the .05 level. 

Source: U.S. Census Bureau, 2011 SIPP-EHC; Survey of Income and Program Participation, 2008 

Panel, Waves 5-8. For information on sampling and nonsampling error see 

<www.census.gov/sipp/source.html>. 
Table 3. Distribution Grade of Enrollment: Calendar Year 2010

Comparison of ACS, CPS, and SIPP-EHC

Population aged 3 and over

(ACS and CPS weighted numbers in thousands.)

Number % Enrolled Number % Enrolled Number % Enrolled

Enrolled in Grade Enrolled in Grade Enrolled in Grade

 Total enrolled in school 82,724 78,519 7,197

 Enrolled in nursery school, preschool 4,950 6.0 4,835 6.2 297 4.1

 Enrolled in kindergarten 4,183 5.1 4,172 5.3 404 5.6

 Enrolled in grade 1 to grade 4 16,338 19.8 16,640 21.2 1,695 23.6

 Enrolled in grade 5 to grade 8 16,567 20.0 16,022 20.4 1,650 22.9

 Enrolled in grade 9 to grade 12 17,235 20.8 16,574 21.1 1,514 21.0

 Enrolled in college, undergraduate years 19,326 23.4 16,354 20.8 1,379 19.2

 Graduate or professional school 4,125 5.0 3,921 5.0 257 3.6

Note: Excludes enrollment in vocational programs. SIPP-EHC weigted to geo-matched SIPP.

Source: U.S. Census Bureau, 2010 Current Population Survey, 2010 American Community Survey, 2011 SIPP-EHC.

ACS CPS SIPP-EHC
Table 4. Comparison of SIPP and SIPP-EHC Monthly Enrollment Rates: Calendar Year 2010

Adults Age 15 and Over

2010 Total % Enrolled Total % Enrolled

January 22,730 17.4 20,600 16.2 1.2

February 22,355 17.9 20,600 16.4 1.5 *

March 21,772 17.7 20,600 16.5 1.2

April 21,272 17.8 20,600 16.6 1.2

May 20,781 17.4 20,600 16.5 0.9

June 20,501 14.3 20,600 13.2 1.1

July 20,179 10.0 20,600 7.2 2.8 *

August 19,810 13.4 20,600 11.5 2.0 *

September 19,629 16.4 20,600 16.8 -0.4

October 19,381 16.3 20,600 16.9 -0.6

November 19,330 16.5 20,600 17.1 -0.6

December 19,342 16.2 20,600 16.9 -0.7

Note: SIPP geo match file is a sub sample of SIPP geographically matched to 2011 SIPP-EHC. SIPP-EHC weighted to 

*Significant difference at the .05 level.

Source: U.S. Census Bureau, 2011 SIPP-EHC; Survey of Income and Program Participation, 2008 Panel, Waves 5-8. F

Geo-matched SIPP SIPP-EHC % Point

Difference

Table 5. October 2010 Monthly Enrollment Rate for Kids

Comparison of CPS and SIPP-EHC

(Numbers in thousands; Population age 3-17)

Age Number % Number %

 3 and 4 years old 4,706 53.2 32.5 19.7 * 859

 5 and 6 years old 7,955 94.5 87.4 6.9 * 835

 7 to 9 years old 12,153 97.7 1,211 96.3 1.6

 10 to 13 years old 15,831 98.2 2,075 97.2 1.1

 14 and 15 years old 7,736 98.1 94.5 3.6 * 391

 16 and 17 years old 7,963 96.1 92.1 4.1 * 806

Note: SIPP-EHC weighted to geo-matched SIPP.

*Significant difference at the .05 level

Source: U.S. Census Bureau, 2010 Current Population Survey, 2011 SIPP-EHC.

CPS SIPP-EHC CPSSIPP-EHC 
0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

Jan

Feb

Mar

Apr

May

June

July

Aug

Sep

Oct

Nov

Dec

Percent enrolled 

Figure 1. Monthly Enrollment of Age 

15 and over in SIPP and SIPP-EHC 

Geo Matched SIPP

SIPP-EHC 2011

SIPP-EHC 2010

Source: U.S. Census Bureau, 2011 SIPP-EHC, 2010 SIPP-EHC, 

and SIPP 2008 Panel, Waves 5-8. For information on sampling and 

nonsampling error see <www.census.gov/sipp/source.html>.