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Wednesday, March 18, 2015

How USDA NASS Counts Acres

ifr150320–31
How USDA NASS Counts Acres
Mark Schleusener, Illinois State Statistician - USDA NASS

USDA has just wrapped up its survey of more than 80,000 U.S. farmers. Todd Gleason reports how the agency uses the information to develop the March 31st acreage forecast.

In the spring USDA’s National Agricultural…
3:01 radio
3:16 radio self contained

In the spring USDA’s National Agricultural Statistics Service division contacts farmers in hopes of learning how much of each crop they expect to plant. The agency contacts farmers across the United States. Corn and soybean farmers are of particular interest. This year more than 4000 Kansas farmers were tapped, along with around 3700 in Nebraska and about 3000 in each of the Dakotas, Iowa, and Illinois. Another 2000 farmers each were contacted in Indiana and Ohio.

Schleusener :06 …so we use what’s called a stratified sample

Quote Summary - Our goal is to make sure we are measuring small, medium, and large farms. So, we use what’s called a stratified sample.

That’s NASS Illinois State Statistician Mark Schleusener.

Schleusener :19 …one out of twenty-five of those.

Quote Summary - That is a fancy way of saying for the biggest farms, we are going to talk to all of them; for the large, but not biggest we will talk with one out of three of those and for the medium, maybe one out of ten; and for the smaller farms we might measure one out of twenty-five of those.

Each farmer surveyed is asked how many acres they operate. How much of that land they intend to plant to corn or soybeans, and how much might already be in wheat. They’re also asked about oats, sorghum, and hay. The response rate goal, and usually achievement, is an amazing eighty percent.

Schleusener :53 …in general, but also are more expensive.

Quote Summary - Yes, our goal is an 80% response rate on all surveys and we use several methods of data collection. Every producer in the sample receives a letter with a planting intentions questionnaire. The letter also has instructions for reporting to a secure internet website. These are both inexpensive ways of gathering data. The people that do not respond will be called. If this doesn’t work then someone will make a farm visit for a face to face. Both these methods are more effective, in general, but also are more expensive.

The biggest problem NASS faces when taking the acreage survey is that farmers usually haven’t yet made all their planting decisions. The agency knows this and is satisfied with best estimates. The individual reports are confidential by law and the data collected is exempt from legal processes.

The data can be aggregated at the county, state, and national level. Computers flag any large acreage changes at the individual level so that an analyst can check for a data entry error or make a follow up call. The state statisticians review the total number of crop acres for any major changes - total crop acres generally remain constant - and then submit the estimates in an encrypted file to USDA NASS in Washington, D.C. There more analysis is done and the final report is produced for release March 31.