0244-nursery production-2016-SSB - Rev. Nov 2016

1Supporting Statement - Part B

Nursery and Christmas Tree Production Survey

OMB No. 0535-0244

B. COLLECTION OF INFORMATION EMPLOYING STATISTICAL METHODS:

1. Describe (including a numerical estimate) the potential respondent universe and any sampling or other respondent selection method to be used. Data on the number of entities (e.g., establishments, State and local government units, households, or persons) in the universe covered by the collection and in the corresponding sample are to be provided in tabular form for the universe as a whole and for each of the strata in the proposed sample. Indicate expected response rates for the collection as a whole. If the collection has been conducted previously, include the actual response rate achieved during the last collection.

The Oregon Christmas Tree and the Oregon Nursery Production, sampling frames are comprised of all Oregon operations with positive Christmas tree acreage and nursery value of sales of at least $10,000, respectively.  The Oregon Christmas Tree Survey and the Oregon Nursery Production Survey are Stratified Simple Random Sample designs.  Operations in the highest strata for both surveys are sampled at 100% and all other strata use previous survey or sampling frame data to derive sample sizes.

The goal of the Oregon Christmas Tree Survey is to publish strata level quantity and revenue information.  Therefore, a strata level target CV of 3.5% was used to determine strata level sample sizes. The Oregon Nursery Production Survey was last conducted as a reimbursable survey in 2010. The precision level for this survey is not available.

Response Rates for the last cycle of each survey.

2. Describe the procedures for the collection of information.

The two Oregon production surveys are designed to be used as mail surveys with either phone or personal interview follow-up for non-respondents. A blank questionnaire, postage paid envelope, and cover letter are mailed to the respondent. A reminder mailing will be sent out to non-respondents a few weeks later. Operators who do not respond to either of the mail requests will be attempted by either a phone enumerator or a personal visit from one of our field enumerators. Our enumerators work for the National Association of State Departments of Agriculture (NASDA) and are trained by NASS to conduct the surveys in a timely and accurate manner.

3. Describe methods to maximize response rates and to deal with issues of non-response. The accuracy and reliability of information collected must be shown to be adequate for intended uses. For collections based on sampling. a special justification must be provided for any collection that will not yield "reliable" data that can be generalized to the universe studied.

Information on the data needs of users is routinely requested and data users are involved in survey content development. Data User meetings are held yearly and give all interested individuals the opportunity to express their data needs. NASS makes every effort to accommodate the needs of the U.S. public. When NASS meets with data users and industry representatives we ask that they convey the message to their members of how important these data collections are to their industry.

NASS’s Public Affairs Office (PAO) is responsible for promoting NASS survey efforts and educating respondents about the need and use for the data they are being asked to provide. PAO works with data users and industry leaders to provide concrete examples of data use. They are also actively publicizing survey activities by generating and distributing news reports and drop-ins for industry publications and news outlets.

For non-response to the Oregon nursery and Christmas tree surveys, after two attempts by mail the Oregon Field Office has their telephone or field enumerators conduct follow-up interviews.

Non-sampling errors occur during a survey process but, unlike sampling variability, are difficult to measure. They may be caused by interviewers failing to follow instructions, poorly worded questions, non-response, problematic survey procedures, or data handling mistakes between collection and publication. In these surveys all survey procedures and analyses were carried out in a consistent and orderly manner to minimize the occurrence of these types of errors.

Keep in mind that the sample design is just one of many factors that influence CVs. CVs are also heavily influenced by the number of positive reports we receive back for a specific item of interest and also the variability in the data on those responses. High end and low end outliers can have a significant impact on CVs, and that impact is even more severe if there are very few positive reports for that item.

NASS continually monitors CV performance in all surveys and always utilizes past survey results when designing the next iteration of a specific survey. We will certainly consider increasing the sample size where CVs were unacceptable to provide reliable estimates while working within our budget constraints for this particular project.

Another way to improve the sample and also CVs is to verify we are using the most current control data as possible when selecting the sample. The Stratified Simple Random Sample design is based on using existing data about an operation and for the proposed study we will ensure that we are utilizing the most recent data available for all operations in our target population.

4. Describe any tests of procedures or methods to be undertaken.

NASS’s experience with previous production surveys has been beneficial in designing the surveys covered in this docket. No testing was conducted.

5. Provide the name and telephone number of individuals consulted on statistical aspects of the design and the name of the agency unit, contractor(s), grantee(s), or other person(s) who will actually collect and/or analyze the information for the agency.

Specifications and survey design are developed by Sampling, Editing, and Imputation Methodology Branch, Methods Division; Branch Chief is Mark Apodaca, (202)720-4008.

Data collection is carried out by NASS Regional Field Offices; the Western Field Operation’s Director is Kevin Barnes (202) 720-8220.

Oregon’s State Statistician is Dave Losh (503) 326-2131. He works with the Oregon State Department of Agriculture to develop the specifications to fulfill the data needs and works to get the External Project Agreements signed and approved.

August 2016

Revised – November 2016