Response to Terms of Clearance

Response to OMB Terms of Clearance for the CEAP Docket (0535-0245)

CEAP response rate computation

The CEAP survey is a sample of points, targeting cropland, from the National Resource Inventory frame developed at Iowa State University  for the National Resource Conservation Service.  NASS enumerators determine the individual operating the field containing each sampled point and conduct interviews to determine if the land is used for the purposes covered by the program and, if qualified, chemical use and production practices in those fields.  Since the interviews are very comprehensive and lengthy, NRCS and NASS agreed that all respondents will have a one interview limit.  Any points that result in a second interview for a respondent are removed from the sample.  Therefore, the operating sample size is less than the original number of points selected.

The response rate is derived as the sum of the completed interviews plus those determined to be out of scope divided by the number of operating samples.  Out of scope are those points falling in fields that are not used for agricultural production or used for commodities not studied under the CEAP.  This would include urban uses like housing developments or commercial use; fruit, nut, nursery, and CRP uses as they are not under continuous cultivation; and recreational use like parks and golf courses.

The response rate (RR) for CEAP is calculated using the following components:

C = number of completed cases or sufficient partials;

R = number of refused cases;

I = number of inaccessible cases;

NC = number of noncontacted sample units known to be ineligible due to respondent burden;

OS = number of eligible sample units out-of-scope or not meeting the selection criteria;

The response rate represents a composite of these components:

RR =	C+ OS
	(C+R+I+OS) - NC

The response rate was originally calculated without removing the number of noncontacted sample units from the sample resulting in a RR= 77.5 percent. These records were entered as nonresponse (inaccessible records) in data entry and when detected, corrective action was taken and reported to our OMB desk officer. Removing the noncontacted sample units from the sample results in a corrected RR=79.6 percent.

Using the corrected RR calculation, NASS met the OMB expected response rate for the 2011 CEAP survey and therefore is not planning a nonresponse bias analysis as instructed in the Standards and Guidelines for Federal Statistical Agencies, Guideline 1.3.4. Therefore, upon correction of the CEAP response rate and discussion with the OMB desk officer, nonresponse bias analysis is not required at this time and that term of clearance is therefore removed.

Our review of response rate calculations for prior waves of CEAP indicated that the response rate reported correctly reflects the formula shown here and the miscommunication of CEAP response rates is limited to the 2011 CEAP response rate noted in the 2012 information collection request.

Dave Aune

Statistical Methods Branch, Chief

National Agricultural Statistics Service

Washington,  DC   20250

David.Aune@nass.usda.gov

202.720.6468