EARTHTRENDS DATA TABLES For more information, please consult http://earthtrends.wri.org TECHNICAL NOTES: AGRICULTURAL PRODUCTION DEFINITIONS AND METHODOLOGY Agricultural production indices (total and per capita) present net production after deduction for feed and seed of a country's agriculture sector relative to the base period 1999-2001. The agricultural production index includes all crop and livestock products originating in each country. Intermediate agricultural inputs, including fodder crops, are not counted. For a given country, the index is calculated as the average annual output of the agricultural sector during the period of interest divided by the average 1999-2001 production. This ratio is then multiplied by 100 to obtain the index number. For example, a per capita production index for 2001-2003 of 90 indicates that total agricultural levels per person in 2001-2003 were 10% less than in 1999-2001. Net production quantities of each commodity are weighted by 1999-2001 average prices using the Laspeyres formula and summed for each year. Each agricultural commodity is assigned an "international" price, which remains the same regardless of the country where it was produced. International prices are calculated using the Geary-Khamis formula. Indices are calculated from net production data presented on a calendar year basis. Total production refers to the average annual mass of output produced in a given country or region during each period. Data are reported in thousand metric tons. Total Area Harvested refers to the area from which a crop is gathered. Area harvested excludes areas which may have been sown or planted but were not harvested due to damage, failure, etc. The "net harvested area" of temporary crops is typically reported, while the "gross harvested area" is usually reported for permanent crops. Gross area can include uncultivated patches, footpaths, ditches, headlands, shoulders, shelterbelts, etc. Data are reported in thousands of hectares. Yields refer to the average annual output produced per unit of harvested area in a given country or region during each period (i.e. yield=total production/harvested area). Data are reported in kilograms per hectare of cropland. Cereals include wheat, barley, maize, rye, oats, millet, sorghum, rice, buckwheat, alpiste/canary seed, fonio, quinoa, triticale, wheat flour, and the cereal component of blended foods. Cereal crops harvested for hay or harvested green for food, feed or silage or used for grazing are excluded, although mixed grains and buckwheat are included. Pulses include beans, lentils, pigeon peas, cowpeas, and vetches harvested for dry grain only. Pulses used for feed are included. Roots and tubers cover all root crops grown principally for human consumption, such as cassava, yucca, taro, and yams. Root crops grown principally for feed such as turnips, mangels and swedes are not included. Meat production data refer to the average annual amount of meat, reported in thousands of metric tons, produced in a given country or region during each period. Data describe total meat production, that is from both commercial and farm slaughter. Data are given in terms of dressed carcass weight, excluding offal and slaughter fats. Total meat production comprises horse meat, poultry meat and meat from all other domestic or wild animals such as camels, rabbits, reindeer and game animals. FREQUENCY OF UPDATE BY DATA PROVIDERS As of August 2004, all data were available through 2003. FAO updates the data annually. DATA RELIABILITY AND CAUTIONARY NOTES Agricultural production data are governed by established accounting practices and are therefore generally considered to be reliable. However, countries vary in the quality of data they have available to report. In the absence of reliable sources or when information for the latest year is not available in time, figures for quantities and values are estimated on the basis of trade returns of trading partners. Problems also arise in compiling these data into internationally comparable agricultural statistics and in estimating data that are missing. Each variable in FAO's database can have as many as 30,000 data points associated with it for different countries and years. Officials need to ascertain, based on limited information, which one of various figures reported by various sources (national publications, FAO questionnaires, international publications, etc.) is the most recent or the most reliable. Variable definitions and coverage do not always conform to FAO recommendations, and therefore may not always be completely consistent across countries. Agricultural Production Indices: Agricultural production indices are not directly measured; they are derived from a set of formulas and algorithms. The calculation therefore contains an unavoidable amount of subjectivity. Reliability is limited by the accuracy and precision of agricultural production and price data. While these data can illustrate rough comparisons and trends over time, rigid score comparisons and rankings are discouraged. The country-level indices reported here may differ from other calculations of agricultural production due to varying concepts of production, coverage, weights, time reference of data, and methods of calculation. Total Production, Yields: Production of subsistence crops is seldom reported in records of sales and processing, resulting in missing data points. Estimates of missing data are usually made by following the observed trend of the commodity in question in previous years, while also considering the trends in neighboring countries. When a complete time series is missing for a particular data set, FAO officials base their estimates on first-hand accounts through country visits and data from neighboring countries. Yields: Data rely on accurate estimates of production and of the sown and harvested crop area. However, in many countries, the sown area is changed annually by governments to control prices and production through subsidies and other programs. Weather, soil quality, and seed availability often affect crop area in developing countries. Total Meat Production: Estimates rely on accurate production figures from processing plants and import/export figures of live animals. Trade data are usually given by number rather than by weight, and the size of domestic animals can vary by a factor of 10 depending on the age and the condition of the animal. As a result, estimates of "average carcass weight" used to determine meat production can vary in accuracy. Cereals: Area data relate to harvested area. Some countries report sown or cultivated area only; however, in these countries the sown or cultivated area does not differ significantly in normal years from the area actually harvested, either because practically the whole area sown is harvested or because the area surveys are conducted around the harvest period. SOURCE Food and Agriculture Organization of the United Nations (FAO), FAOSTAT on-line statistical service. Available on-line at http://apps.fao.org . FAO: Rome, 2004.