Supporting Statement – Part B
(Forms RD-1 and RD-1A)
Collection of Information Employing Statistical Methods
1. Description of Universe and Respondent Selection
Approximately 32,000 companies will be selected annually during the clearance period to represent the approximately 2 million companies with 5 or more paid employees in all private non-farm sectors of the economy. The sampling frame of 2 million companies will be created by aggregating establishment information from the Census Bureau's Business Register (BR) into a file of enterprises.
Based on the response rates for the 2005 cycle of the Survey and as summarized in the table below, the expected response rate for respondents that receive the Form RD-1 (3,426 companies) will be approximately 79 percent. The response rate for respondents that receive the Form RD-1A (28,574 companies) is expected to be approximately 78 percent, yielding an overall response rate of 78%. Expected response rates are summarized in the following chart:
Category |
Number of companies in the universe |
Number of companies in the sample |
Expected response rate in percent |
All companies |
2,060,803 |
32,000 |
78 |
Top 300 R&D performing companies1 |
300 |
300 (298 RD-1 2 RD-1A) |
90 |
Remaining Form RD-1 companies |
3,128 |
3,128 |
77 |
Form RD-1A companies |
2,057,375 |
28,572 |
78 |
2. Procedures for Collection of Information
The sample design for the Survey is complex. The design takes advantage of several pieces of information concerning the conduct of R&D. They are (1) current year information from the Business Register, (2) information about R&D reporting from the Survey over the past 5 years, (3) information from the Bureau of Economic Analysis about R&D performance, (4) information from various trade associations about R&D performance, and (5) information from the Company Organization Survey (COS) about R&D performance. It is estimated that about 2 percent of all U.S. companies perform R&D so additional information about R&D reporting is used to make the sample more efficient.
Partitioning of the frame – The sampling frame of approximately two million companies is first partitioned into two groups. Group 1 consists of companies that have responded to the Survey at least once in the past five years, or companies that have responded to the COS. That is, Group 1 consists of companies where the status (yes/no) of R&D is known from past surveys. Group 2 consists of the remaining companies; Group 2 consists of companies where the status of R&D is unknown. See table 1 for details.
Group/Category |
Population Size |
Group 1 – Known R&D status |
99,194 |
G1C1 - > $3 million (most recent positive R&D) |
3,610 |
G1C2 - < $3 million (most recent positive R&D) |
11,366 |
G1C3 - $0 R&D (2001 – 2005) (certainties) (noncertainties) |
84,218 566 83,652 |
Group 2 – Unknown R&D status |
1,750,174 |
G2C1 - Top 50 by state or industry |
4,259 |
G2C2 - remaining |
1,745,915 |
TOTAL |
1,849,368 |
Stratifying the categories – One of the major goals of the survey is to provide estimates of R&D performance at the industry level. To provide enough sample by industry group, the categories are stratified. Group 1 category 1 (G1C1) is a certainty stratum. Group 1 category 2 (G1C2) is stratified into 50 industry groups. Group 1 category 3 (G1C3) is stratified into two strata: certainties and noncertainties. Group 2 category 1 (G2C1) is a certainty stratum. Group 2 category 2 (G2C2) is stratified into the same 50 industry groups as G1C2. Table 2 summarizes these categories.
Table 2 - 2006 Strata
Categories |
Strata Definitions |
Group 1 – Known R&D status |
|
G1C1 - > $3 million (most recent positive R&D) |
Certainty strata – take all |
G1C2 - < $3 million (most recent positive R&D) |
Stratify into 50 industry groups |
G1C3 - $0 R&D (2001 – 2005) |
Stratify into 2 broad strata – certainties (companies with active establishments in NAICS 5417 or from BEA file) and noncertainties |
Group 2 – Unknown R&D status |
|
G2C1 - Top 50 by state or industry |
Certainty strata – take all |
G2C2 - remaining |
Stratify into 50 industry groups |
Industry classification - Each company in the frame is assigned one single 6-digit North American Industry Classification System (NAICS) code regardless of the number of business activities the company conducts. The NAICS code is assigned using a hierarchical 4-step procedure.
Step 1 - Determine the company’s economic sector (2-digit NAICS or combination of 2-digit NAICS) that accounts for the highest percentage of its aggregated payroll.
Step 2 - Determine the company’s economic subsector (3-digit NAICS) that accounts for the highest percentage of its payroll within the assigned economic sector.
Step 3 - Determine the company’s 4-digit industry code that accounts for the highest percentage of its payroll within the assigned economic subsector.
Step 4 - Determine the company’s 6-digit industry code that accounts for the highest percentage of its payroll within the assigned 4-digit industry code.
The industry stratification is based on the 4-digit NAICS code. In 2006, the 50 industry groupings consisted of 28 manufacturing groups, such as food, chemicals, computers or aerospace products and 22 nonmanufacturing groups, such as trade, utilities, or professional services. For a complete list of the 2006 industry groups, see table 3 below.
Table 3 – 2006 Industry Groups
Survey Industry Group |
NAICS |
01 |
311 |
02 |
312 |
03 |
313-316 |
04 |
321 |
05 |
322-323 |
06 |
324 |
07 |
3251 |
08 |
3252 |
09 |
3254 |
10 |
other 325 |
11 |
326 |
12 |
327 |
13 |
331 |
14 |
332 |
15 |
333 |
16 |
3341 |
17 |
3342 |
18 |
3344 |
19 |
3345 |
20 |
other 334 |
21 |
335 |
22 |
3361-3363 |
23 |
3364 |
24 |
other 336 |
25 |
337 |
26 |
3391 |
27 |
other 339 |
28 |
unclassified manufacturing, i.e. NAICS = 3100 |
30 |
21 |
31 |
22 |
32 |
23 |
33 |
42 |
34 |
44, 45 |
35 |
48, 49 |
36 |
5111 |
37 |
5112 |
38 |
5171, 5172 |
39 |
5174 |
40 |
other 517 |
41 |
5181 |
42 |
5182 |
43 |
other 51 |
44 |
52, 53 |
45 |
5413 |
46 |
5415 |
47 |
5417 |
48 |
other 54 |
49 |
621-623 |
50 |
55, 56, 61, 624, 71, 72, 81 |
00 |
unclassified, i.e. NAICS = 0000 |
Sampling methodology – To be as efficient as possible in the sampling, companies with positive known R&D are over sampled at sufficiently higher sampling rates to provide enough sample to produce industry level estimates. In addition, companies within certain states are over sampled at higher sampling rates to provide enough sample to produce state level estimates. This strategy resulted in enough sample to produce state by industry level estimates.
The sample selection methodology differed in the different categories.
In the three certainty strata (G1C1, G2C1 and part of G1C3), all companies are selected for the sample. These companies are important to the sample because they are either known to conduct a large amount of R&D or are known to have large payrolls in a state or industry group and may be more likely to conduct R&D or have R&D labs.
Probability proportionate to size (PPS) sampling is used to select companies within the 50 industry strata in G1C2 and G2C2. In G1C2, size is based on prior year reported R&D. In G2C2, size is based on payroll. The probabilities of selection are determined such that a company that is large relative to other companies in a given state or in a given industry has a higher probability of selection than a ‘smaller’ company.
Simple random sampling (SRS) is used to select companies in the noncertainty portion of G1C3. It is possible, but not highly likely, that these companies are conducting R&D in the current year. Companies in the manufacturing stratum are selected with the same probability as those in nonmanufacturing. This sampling probability was 0.01. Table 4 summarizes the various sampling methodologies for each category.
Table 4 – Sampling Methodologies
Categories |
Strata Definitions |
Sampling methodology |
Group 1 – Known R&D status |
|
|
G1C1 - > $3 million |
Certainty strata |
Take all |
G1C2 - < $3 million |
Stratify into 50 industry groups |
PPS with state & industry constraints |
G1C3 - $0 |
Stratify into 2 broad strata – certainties and noncertainties |
Take all for certainty portion and SRS for noncertainty portion |
Group 2 – Unknown R&D status |
|
|
G2C1 – Top 50 by state or industry |
Certainty strata |
Take all |
G2C2 – Remaining |
Stratify into 50 industry groupings |
PPS with state & industry constraints |
Sample size – The overall sample size of roughly 32,000 is based on a combination of desired degree of precision at the industry or state level and on staffing and budget resources. Some initial overall constraints were set. (1) A minimum probability of selection was set at .01 for companies in manufacturing industries so that the maximum weight of any of these companies would be 100. (2) A minimum probability of selection was set at .004 for companies in nonmanufacturing industries so that the maximum weight of any of these companies would be 250. (3) Roughly ¾ of the sample was to be selected from the known positive R&D performers. (4) The sampling fraction for the noncertainty portion of the known zero group was set at 1 in 100. All of these constraints, along with the specified CV constraints, were set so as to meet the desired total sample size of roughly 32,000 companies. The final 2006 sample sizes by strata are shown in table 5 below.
Table 5 – 2006 Industry R&D sample sizes
Categories |
Population size N |
Sample size n |
|
Group 1 – Known R&D status |
99,194 |
12,656 |
|
G1C1 - > $3 million |
3,610 |
3,610 |
|
G1C2 - < $3 million |
11,366 |
7,643 |
|
G1C3 - $0 certainties noncertainties |
566 83,652 |
566 837 |
|
Group 2 – Unknown R&D status |
1,750,174 |
19,428 |
|
G2C1 – Top 50 by state or industry |
4,259 |
4,259 |
|
G2C2 – Remaining |
1,745,915 |
15,169 |
|
Total |
1,849,368 |
32,084 |
Roughly 54 detailed statistical tables are produced each year from the Survey, including point estimates and coefficients of variation. For a majority of the estimates, the Horvitz-Thompson (H-T) estimator and variance is computed.
The H-T estimator can be expressed as2:
where
is the measurement for the ith
unit
is the probability that the ith
unit is in the sample > 0 (i
= 1, 2, … N)
is the weight associated with the ith
unit
The variance of the H-T estimator is given by:
where
is the probability that the ith
and jth
units are both in the sample
This is the true variance if the entire population is known.
The H-T estimator is design-unbiased and preserves desired additive properties within and across published tables. That is, the sum of the estimated R&D across all industries or across all states adds to the estimated U.S. total.
For state level estimates, presented in only three tables, a modified synthetic estimator is used3. This estimator preserves the desired additive properties yet provides smoother estimates over time for rare event populations, such as R&D by state.
The new estimator used to produce state estimates from the R&D survey has the following form:
where
and
N = population size
Nh = population size of stratum h
NI = number of independent non-aggregate industry publication tabulations
L = Number of sampling strata
yShk = reported or imputed R&D in state S of kth company in stratum h
yIhk = reported or imputed R&D in industry I of kth company in stratum h
whk = weight of kth company in stratum h, = reciprocal of probability of selection
ahk = one (1) if kth sampling unit in stratum h is selected and zero (0) otherwise
XISk = payroll in industry I and state S of kth company, available from the frame
XIi = payroll in industry I of kth company, available from the frame
= probability of selection of kth company
Payroll by industry and state is first obtained at the establishment level then rolled up to a company level. It should be noted that a company can have payroll in more than one industry or state. The numerator of RIS is the expected value of the payroll of any given state within a given industry from companies that are not selected. The denominator of RIS is the expected value of the payroll of a given industry from companies that are not selected. Companies selected with certainty do not figure in the calculation of RIS.
The estimator itself can be decomposed into two major parts. The first part is the unweighted sum of the reported or imputed R&D in the state of interest. This value is the lower bound of all possible values of the true value given the selected sample. The second part is the portion of the difference between the weighted and unweighted R&D that is allocated to the state.
To obtain the variance of the modified
synthetic estimator, the sample variance for the H-T estimator can be
modified by replacing yShk with
,
where
.
And the modified state estimator can be re-expressed as
.
The design coefficients of variation used to determine sample sizes by strata vary from 0.35% on overall totals to 6.8% for industry level estimates. Achieved relative standard errors (RSE) for the 2005 estimates differed from the pre-specified design levels. The RSEs on overall totals ranged from 0.7% on budgeted R&D to 11.6% on the total number of nanotechnology companies. The RSEs on subtotals at the manufacturing or nonmanufacturing level ranged from 0.3% on total manufacturing foreign R&D to 19.7% on the total number of nanotechnology companies. RSEs vary greatly at the individual industry and state level with the majority under 3.0% for manufacturing industries and under 7.0% for nonmanufacturing industries.
3. Methods to Maximize Response and Account for Nonresponse
Follow-up procedures - Form RD-1 companies will continue to have 60 days to report. Reminder letters will be sent to companies that have not responded by mid-May, unless they have been granted extensions. Follow-up letters will be sent in late May, June, and July. The first follow-up package sent in late May will include a duplicate form. In addition, Census Bureau staff will telephone companies among the largest 500 R&D performers that have not returned a survey form or requested a filing time extension rather than send the second and third notice. These companies account for as much as 85 percent of the value of the data and their responses are critical for the completeness of the estimates. Form RD-1A companies that do not respond within 30 days are sent follow-up letters in April, May, June, and a phone follow-up in July (or until a response is received). Each mail follow-up package includes a duplicate form.4
Estimating for missing data - Estimates for Form RD-1 nonrespondent companies are made for total R&D spending based on the company’s previous years' data and the change from the prior to the current year for responding companies in the same industry. The distributions of expenditures for nonrespondent companies or for partial respondent companies are based on the distribution for the company in the prior year. If the company has no previous distribution of expenditures, an attempt is made to impute data for only selected items based on the distribution of data for companies in the same industry. For Form RD-1A companies that were not selected in the prior year sample, total R&D spending is imputed based on the average expenditure in the current year for responding companies. R&D expenditures for selected data items are imputed for nonrespondent or partial respondent companies. This imputation is based on the average distribution of expenditures for responding companies.
Survey form redesign for improved response – Both survey questionnaires and the accompanying instructions were previously redesigned as a result of the conversion to the Census Bureau’s Generalized Instrument Design System (GIDS), extensive review by NSF and Census Bureau staff, cognitive testing, and review by a noted survey methodologist who specializes in survey questionnaire design5 (see Attachments 2 and 3 for copies of the current survey instruments and Attachments 4 and 5 for the proposed survey instruments for 2007). NSF and the Census Bureau will continue redesign efforts, which will include extensive testing and evaluation of proposed changes, in an effort to make response to the survey less burdensome. During the next clearance period, we plan to continue sending the Form RD-1 to companies that perform $3 million or more of industrial R&D.6 The Form RD-1 will continue to include questions that probe company ownership, sales, total employment, R&D employment, R&D expenditures, R&D costs budgeted for the next year, R&D performed by outside organizations, R&D performed abroad, R&D funded by Federal government agencies, the types of costs incurred for R&D, R&D costs distributed by state, energy-related R&D the cost of fringe benefits for R&D personnel; the cost of R&D performed in three technology areas (biotechnology, software development, and materials synthesis and processing) and how much of the cost could be attributed to nanotechnology; and the cost of R&D performed by others outside of the company by type of organization.
4. Tests of Procedures or Methods
NSF and the Census Bureau plan further redesign of the survey questionnaires and instructions, and other methodological research and improvements to the Survey. To research and implement survey improvements, especially those resulting from the CNSTAT recommendations, a significant amount of cognitive and usability testing is planned.
5. Contacts for Statistical Aspects and Data Collection
Persons responsible for sample design and selection:
Paul L. Hsen, Assistant Division Chief
Research and Methodology
Manufacturing and Construction Division
U.S. Census Bureau
(301) 763-4586
(301) 763-7783 (FAX)
Stacey J. Cole, Chief
Manufacturing Programs Methodology Branch
Manufacturing and Construction Division
U.S. Census Bureau
(301) 763-4771
(301) 763-4718 (FAX)
Jock Black, Senior Mathematical Statistician
Division of Science Resources Statistics
National Science Foundation
(703) 292-7802
(703) 292-9092 (FAX)
Person responsible for data collection:
Julius Smith, Jr., Chief
Special Studies Branch
Manufacturing and Construction Division
U.S. Census Bureau
(301) 763-7662
(301) 763-4718 (FAX)
Person responsible for analysis of the statistics and publication:
Raymond M. Wolfe, Economist
Research and Development Statistics Program
Division of Science Resources Statistics
National Science Foundation
(703) 292-7789
(703) 292-9091 (FAX)
Attachments
Cover Letter
Survey Questionnaire (Draft 2007 Form RD-1)
2A. Draft Instructions for the 2007 Form RD-1
Survey Questionnaire (Draft 2007 Form RD-1A)
3A. Draft Instructions for the 2007 Form RD-1A
1The response rate for the largest 300 industrial R&D performers for the 2003, 2004, and 2005 cycles of the Survey was 91%, 88%, and 90%, respectively.
2Sampling Techniques 3rd Edition, William G. Cochran, John Wiley & Sons, 1977.
3 A Hybrid Estimation Approach to State Level Estimates in the Survey of Industrial Research & Development, Slanta and Mulrow, presented at the 2004 Joint Statistical Meetings in Toronto.
4 In the past all respondents were asked to return the survey form within 60 days. Beginning with the 1998 survey, respondents sent Form RD-1A are asked to return the form within 30 days. Since nearly all companies sent Form RD-1A do not conduct R&D, and since the Census Bureau has made it much easier for them to report through the introduction of TDE, this has improved response without adding burden.
5 Professor Donald A. Dillman, University of Washington, is under contract with both NSF and the Census Bureau to give expert advice on survey issues. Dr. Dillman recently used the Form RD-1 as a teaching example in a seminar sponsored by the Census Bureau entitled “Questionnaire Design: Issues for Business Surveys.”
6 All other companies will be sent Form RD-1A, the abbreviated survey form that collects basic information about R&D expenditures and character of work (ie, basic and applied research and development).
File Type | application/msword |
File Title | NEEDS TO BE UPDATED BY THE R&M STAFF |
Author | smith001 |
Last Modified By | allen001 |
File Modified | 2007-10-18 |
File Created | 2007-09-12 |