1. Linking Population and Housing Censuses with Agricultural Censuses
Regional Roundtable
World Programme for the Census of Agriculture Port of Spain, Trinidad and Tobago May 2017
Linking Population and Housing Censuses with Agricultural Censuses
Technical Session 4
Oleg Cara
Agricultural Census and Survey Team
FAO Statistics Division

2. Contents Background Relationship between the PHC and the AC
Ways to link PHC and AC
Main advantages of linking both censuses
Collecting agricultural data in the PHC
Questions related to agriculture in the PHC
Country experiences

3. Background
Historically population censuses and agricultural censuses were undertaken as two independent and separate operations.
Experience has shown that the coordination and linkage of both operations have desired consequences reducing costs, improving the building of frames for the agricultural census, increasing the overall quality of the censuses.
The FAO World Programme for the Census of Agriculture 2020 (WCA 2020) strongly recommends that countries coordinate the agricultural census (AC) with the population and housing census (PHC), during the early stages of census planning.

4. CA and PHC: Some features
Statistical units:
In the PHC: the household;
In the AC: the agricultural holding.
The common unit is the household engaged in own-account agricultural activities.
Normally, there is only one agricultural holding in a household, and it is this one-to- one correspondence which allows integration of the two censuses. Other cases can be dealt with in several ways in order to match the holdings to the households. In practice, countries decide on the most suitable approach in their context.
Ways to coordinate both censuses:
Use of common concepts, definitions and classifications;
Sharing field materials;
Using the listing of the population census as a starting point for the frame for the household sector of the agricultural census;
Collecting agriculture data as additional items in the population census, either as basic items or frame items through an agriculture module.

5. Main advantages of linking both censuses
Reduction of the total cost of the two censuses (the same infrastructure, logistics, equipment can be used for both censuses);
Reduction of the scope of the agricultural census;
Enrichment of data analysis from the two censuses;
Ensuring regular agricultural census operations;
Obtaining a reliable frame for the agricultural census;
Optimization of sampling designs of the agricultural census;
Better defining the agricultural census coverage.
The next slides provide more details on some of these advantages

6. Obtaining a reliable frame for the agricultural census
Access to an up-to-date and reliable frame of agricultural holdings – including both household and non-household operated holdings - is a major problem for the census of agriculture in many developing countries.
The frame of agricultural holdings in the non-household sector can be fairly readily compiled from land and business registers, lists of large/commercial farms and other administrative and statistical sources.
Building a frame of household-operated agricultural holdings is a much larger and more complex task. It effectively means visiting all private households to establish the extent of agricultural activity in each, and how many separate holdings household members are engaged in. The PHC provides a unique opportunity for identifying all agricultural households, including in urban areas, for developing an up-to-date, reliable frame as a starting point for agricultural censuses and surveys.

7. Optimization of sampling designs of the agricultural census
In many developing countries, particularly in Africa, agricultural censuses are conducted using large samples to generate results at small administrative unit level. Agricultural information collected during the population and housing census can be used to improve sample design and identify optimal sample size, e.g.:
To better stratify and allocate the sample between strata and between different stages - when multi-stage cluster sampling is used;
To provide an up-to-date size measure - when probability proportional to size (PPS) method is used.

8. Better defining the agricultural census coverage
Minimum size limits, on variables such as numbers of livestock, numbers of tree crops, area of land, value of annual sales, and purpose of production are used in most countries to determine whether a household’s agricultural activity qualifies as a holding or not. This basic information can be collected during the PHC through the standard visitation record or through a separate section in the household questionnaire.
The information can also be collected as part of the pre-census cartography and fieldwork. In addition to providing a frame, this has advantages for the design of the agricultural census.
For example, based on the agriculture-related information collected during the PHC the minimum size criteria can be set for the AC. Efforts, and resources for data collection in the AC could then be focused on the more productive holdings.

9. Collecting agricultural data in the PHC
Two topics regarding agriculture-related items are recommended by UN in the Principles and Recommendations for the PHC 2020 round to be included in the PHC:
At the household level, information is collected to identify households engaged in own-account agricultural production;
At the individual person level, information is collected to identify persons involved in agricultural activities during a long reference period, such as a year before the census.

10. Collecting agricultural data in the PHC (cont’d.)
Identification of households engaged in own-account agricultural production is especially useful for establishing a frame for a subsequent agricultural census and surveys.
For this purpose, the basic items recommended by the WCA 2020 to be included in a PHC are:
Whether the household is engaged in any form of own-account agriculture production;
Measure of farm size, such as the area of land (or number of plots) used for agricultural production purposes, and the number of livestock.
Information on forestry, fishery and aquaculture activities may also be collected through the population and housing census in cases when they are important for a country. This information would facilitate the preparation of the frame when countries wish to conduct a subsequent agriculture census which goes beyond the scope of agriculture

11. Collecting agricultural data in the PHC (cont’d.)
Countries wishing to collect more extensive data on agriculture may include an agriculture module in the population and housing census, consisting of a selection from the listed frame items of WCA 2020, such as:
Item 0101: Identification and location of agricultural holding;
Item 0107: Main purpose of production of the holding
Item 0201: Total area of holding
Item 0301: Use of irrigation on the holding: fully and partially controlled irrigation
Item 0401: Types of temporary crops on the holding
Item 0405: Types of permanent crops on the holding and whether in compact plantations
Item 0502: Number of animals (by livestock types relevant for the country) Item 1201: Presence of aquaculture on the holding
Item 1301: Presence of woodland on the holding
Item 1401: Engagement of household members in fishing activity

12. How to collect the agriculture related data?
The required household-level information can be collected as part of the main enumeration. In the case of the basic items these can alternatively be included in the pre-census listing/cartographic phase of the population census so as not to overburden the PHC questionnaire.
The latter approach has an additional advantage that the frame for the AC can be compiled directly from the listing/cartographic exercise without having to wait for the questionnaire to be processed.
The inclusion of an agriculture module or some agriculture-related frame items in the PHC can be useful for countries planning to conduct the AC as a modular approach. In this case the core module AC can be collected during the PHC and the agriculture census would focus on the supplementary modules, conducted on a sample basis.

13. Country practices Panamá – Seventh Nat’l Agricultural Census 2011
The Population Census 2010 was carried out less than one year before the Agricultural Census and a question in the population census allowed identification of households engaged in agriculture.
23. Here or in a different place, has any member of this household…
Sowed any kind of grains (rice, maize, beans or others), cassava, yam, taro, vegetables, sugarcane or other crops in 2009? Yes/No
Grown fruit plants or trees or wood trees or pastures? Yes/No
Grown medical/ornamental plants for commercial use? Yes/No
Raised cows, pigs, horses, mules, donkeys, sheep, goats? Yes/No
Raised chickens, ducks, gooses, turkeys, quails, hives? Yes/No

14. Many thanks