FAO July 2022

This document provides a brief overview of the underlying methodology to forecast import gaps and export surpluses for fertilizer. It also includes a brief description of the data used and the methods applied to standardize and aggregate and to eventually nowcast and forecast the timeseries

TDM database:  The principal source of all trade data used for the analyses is the “Trade Data Monitor”, or TDM for short. TDM is a commercial data supplier, offering a comprehensive and up-to-date global trade dataset at the monthly frequency. TDM covers the entire product space of merchandise trade at different levels of aggregation. Data are encoded according to the Harmonized System (HS), which is the main international classification standard for trade reporting and analysis. Default levels of international comparable aggregation include HS2, HS4 and HS6. In addition, data are available at “tariff-line levels”. While tariff line information provides a more granular level of disaggregation than HS6, there is no assurance of comparability of product definitions across countries. Therefore, to ensure comparability and historical consistency, only data at the three HS levels of aggregation were used for this assessment, whereby the specific needs of the analysis determined the level of disaggregation chosen. Currently, TDM covers trade flows for 113 individual reporting countries and more than 200 partner countries and thus accounts for about 95 percent of trade in agriculture and a similar share of trade in all other merchandise products, including fertilizer. TDM coverage rates for country reporters are everincreasing, thus improving global capture rates. To further enhance the available data coverage in the absence of missing reported data, numerous imputation techniques are applied to the raw data obtained from TDM. The principal goal of these imputation techniques is to supplement the existing data and thus broaden coverage over countries, flows, years and months. The most important imputation technique is known as “mirroring”, i.e. supplementing data for non-reporting countries with flows from reporting partners. While mirroring of missing data is a widely accepted and adopted imputation process, its efficacy is critically limited by the overall availability of data from trading partners. With 113 reporting countries, TDM offers excellent availability of reported data for all major regions, perhaps with the notable exception of sub-Saharan Africa. But also here, data coverage after mirroring yields a near complete global picture of fertilizer trade.

See more: https://www.fao.org/3/cc0849en/cc0849en.pdf