International trade and transit trade; value and weight

What is covered by the survey?

Purpose

The international trade and transit trade statistics give insight into the international commodity flows from, to and through the Netherlands.

Domain description

The statistics of import, export and transit trade measure the international, physical goods flows that are unloaded, loaded, delivered or dispatched on Dutch territory in Europe.
The statistics consist of the StatLine table International trade and transit trade; value, weight, goods, transport mode.
The table describes the value and gross weight of international goods flows broken down by commodity group, transport mode, cargo type (containerized or non-containerized goods), country group of origin or destination and country group of loading or unloading. The following commodity flows are distinguished: total inbound transport, total imports, imports for domestic use, imports for re-exports, total inbound transit trade, inbound quasi-transit trade, total outbound transport, total exports, exports of Dutch products, re-exports, total outbound transit trade, outbound quasi-transit trade. For the years up to and including 2020, the following commodity flows are also given: inbound and outbound transport transit trade, balance customs warehouse storage and customs warehouse transit trade.
The definitions of these commodity flows can be found in the table explanation of the above-mentioned StatLine table.

Start of the survey

These statistics cover the period from 2007 onwards.

Frequency

Annually.

Publication strategy

Generally, new, provisional figures become available approximately one year after the end of the reporting year. Figures on international commodity flows are subject to adjustment when new or updated source data become available. As a result, the status of the figures will be provisional for a longer period of time.

How is the survey conducted?

Key sources

The international trade and transit trade statistics integrate statistics of international trade in goods and statistics on maritime transport, inland shipping, rail transport, road transport, air transport and pipeline transport. Dutch road transport data have been supplemented with data on road transport from other EU member states to and from the Netherlands. The values of imports, exports, re-exports, quasi-transit trade and customs warehouse flows are based on international trade statistics. The gross weights of these flows are also based on international trade statistics. Transport statistics constitute the basis for data on gross weight by transport mode. In addition, data on fossil fuel reserves are derived from the energy balance sheet.

Global structure integration framework

The statistics of import, export and transit trade are based on integration of the international trade in goods statistics and the transport statistics for six modes of transport. On micro-level (trade transactions), trade volumes were converted into gross weights and the transport mode of trade has been checked and corrected. To ensure comparability with the trade figures, the transport weights in non-specific commodity groups (especially general cargo) have been assigned to specific commodity groups. Furthermore, a correction has been made to the maritime and road transport figures to prevent double counting of the roll-on-roll-off transport. Using value-to-weight ratios per year, flow direction, commodity group and transport mode, the value of the goods transported was estimated. After aggregation to the 20 commodity groups, six transport modes, two cargo types (containerized or non-containerized goods) and 36 country groups, a Bayesian integration model was used to improve data consistency.

Due to the loss of customs data on customs warehouse flows, initial estimates for transport transit trade will be made from reporting year 2021 onwards according to:

→ Inbound transport transit trade = βIR * Inbound transport
→ Outbound transport transit trade = βUR * Outbound transport

The fractions βIR and βUR can differ per combination of commodity group, transport mode, cargo type and country group and are derived based on historical data.
The customs warehouse storage and customs warehouse transit trade are now derived from the following equations for total inbound and outbound transport:

→ Inbound transport = Imports for domestic use + Imports for re-exports + Inbound quasi-transit trade + Inbound transport transit trade + Balance customs warehouse storage (applies to value and gross weight)
→ Outbound transport = Exports of Dutch products + Re-exports + Outbound quasi-transit trade + Outbound transport transit trade + Customs warehouse transit trade (value and gross weight)
The Bayesian integration model ensures that data by commodity group, transport mode, cargo type and country group meet the following logical restriction:
→ All commodity flows ≥ 0 (value and gross weight)

Furthermore, for all commodity groups the following must apply:

→ Imports for re-exports ≤ Re-exports (value)
→ (1 – βW) * Imports for re-exports ≤ Re-exports ≤ (1 + βW) * Imports for re-exports (gross weight)
→ (1 – βQ) * Inbound quasi-transit trade ≤ Outbound quasi-transit trade ≤ (1 + βQ) * Inbound quasi-transit trade (gross weight)
→ (1 – βR) * Inbound transport transit trade ≤ Outbound transport transit trade ≤ (1 + βR) * Inbound transport transit trade (value and gross weight)
→ | Balance customs warehouse storage – Customs warehouse transit trade | < βO * Customs warehouse storage capacity

For the parameters βW, βQ, βR and βO, small fractions are chosen so that, for example, inbound and outbound quasi-transit trade flows do not differ from each other by more than a few percent in total weight.

The ratios between value and gross weight are kept within fixed lower and upper limits. These lower and upper limits are determined per commodity group, transport mode and cargo type and are derived from the (processed) international trade figures.

The equations exclude the inbound and outbound transport of goods that are not destined for the market. Among others, this concerns used packaging, removal goods, luggage accompanied by travelers, used equipment from construction companies and fairs and vehicles transported for repair purposes. The weight of these specific goods is added to the transport after applying the model. The (trade) value of these goods is assumed to be nil.

The international trade statistics register the shipment of goods from the country of origin to the Netherlands and the shipment of Dutch products to the country of destination. The transport statistics record the last country where the goods were loaded on the transport means that took the goods into the Netherlands. Furthermore, the transport statistics record the first country where the goods are unloaded from the transport means that brought the goods outside the Netherlands. Therefore, a link has been made between the country groups of origin in trade statistics and the country groups of loading in transport statistics. This has been done by determining for each country group the chances of the goods being transhipped in the other country groups for transport to the Netherlands. This was carried out for each combination of commodity group, mode of transport and cargo type. For this computation, insights from the theory of gravitation models were used. The same method was applied for the outgoing flows. The results were then used to convert the transport data per country group of loading or unloading into data per country group of origin or destination.

The model cannot ensure that the data meets all the restrictions in all cases. Therefore, after testing the model results, a post-processing takes place. This post-processing increases the consistency of the data with the logical restrictions.

Due to the integration method and definition differences, the figures in the StatLine table on international trade and transit trade can vary from figures in other tables on international trade and transport. After the integration of international trade and transport statistics, estimated imports and exports data differ from the original imports and exports data according to the international trade statistics. These differences are modest, usually less than 6 percent. The differences arise because trade figures are slightly adjusted to make sure that the above-mentioned restrictions are met. Adjustment always takes place within the pre-estimated reliability margins around the original figures. The estimated transport totals after integration and the totals in the original transport statistics usually differ by less than 9 percent. These differences are due to the fact that the integration of trade and transport statistics leads to a more complete description of transport and to adjustment within the estimated margins. Furthermore, the figures on total transport published in other tables are generally expressed in terms of gross-gross weights (i.e. including container weight) instead of gross weights.

What is the quality of the results?

Sequential comparison

From 2008 onwards, data on imports and exports are calculated in a slightly different manner compared to the preceding years as a result of the revised definition of re-exports and quasi-transittrade and the inclusion of several companies which, in the past had incorrectly not been included in international trade statistics. The total volume of imports remains virtually unchanged. The value of exports in 2008 is estimated to be 3 billion euros (less than 1 percent of the total) lower than if these changes would not have been implemented. This difference remains within the reliability margins for integrated trade and transport figures. At a more detailed level, relatively larger differences may occur. This change has no consequences for total transport and the estimated transit trade. More information about this break in the series and its effect on international trade statistics can be found in the additional survey description Internationale goederenhandel, trendbreuk 2007-2008 (only available in Dutch).

International data on imports and exports for 2013 are not entirely comparable with those for 2012, as the revised figures for 2013 are based on an improved estimation method for ‘refuelling (bunkering) in international shipping and aviation'. The implementation of the new method caused exports to rise by nearly 5 billion euros in 2013 relative to 2012. This difference also remains within the reliability margins.

Simplified company declarations, an adjusted definition of re-exports and a number of quality upgrades have been introduced in 2015. As a result, the international trade figures for 2015 are not completely comparable with those for 2014. The effect of this break in series is that exports for the year 2014 will be almost 10 billion euros lower and imports will be almost 9 billion euros lower. More information about this break in the series and its effect on the figures can be found in the additional survey description Oorzaken methodebreuk internationale goederenhandel, 2014-2015 (only available in Dutch).

As a result of new insights, trade flows have been revised as of the statistical year 2015. In addition to the method break 2014/2015, the total goods export is 8 billion euro lower as a result. This is 10 billion euros less for total goods imports.

The break in the trade figures between 2014 and 2015 is largely caused by an improvement in the demarcation between re-exports and quasi-transit trade. As a result, part of the imports for re-exports has been transferred to the incoming quasi-transit trade. Part of the re-exports has shifted to the outgoing quasi-transit trade.

Due to the disappearance of customs data on Dutch warehouse flows from 2022, the method of deriving the figures in this table has changed. In order to describe the trend for 2021-2022 as accurately as possible, the new method has also been applied for 2021. The result is that from 2021 onwards the table does no longer contain data on customs warehouse storage, customs warehouse transit trade and transport transit trade. Total transit trade – i.e. the sum of quasi-transit trade, transport transit trade and customs warehouse transit trade – is still estimated as of 2021, as is quasi-transit trade.

Due to progressive insights, the trade and quasi-transit trade flows have been revised as of reporting year 2022. The size of the break has been estimated for 2021 by comparing methods. Total imports are about 5 billion euros higher and 11 billion kilograms lower due to this break. Total exports are about 1 billion euros and 23 billion kilograms lower. In addition, a larger part of the trade value is attributed to quasi-transit trade. On the inbound side, quasi-transit trade was adjusted upwards by 23 billion euros and 19 billion kilograms and on the outbound side by 32 billion euros and 20 billion kilograms. Because of the revision, the figures for 2022 are not exactly comparable to those for 2021. More information about the method break can be found in the overview International Trade in Goods in 2021, difference in value in billions of euros.

As a result of a redesign of the maritime statistics, the transport of LNG (liquefied natural gas) by sea will be classified under the commodity group natural gas instead of petroleum products from 2022 onwards. As a result of the change, the total inbound transport of natural gas by sea will be approximately 13 billion kilograms higher in 2022. The total inbound transport of petroleum products by sea will be approximately 13 billion kilograms lower. As a result of this change, the figures for natural gas and petroleum products in 2022 are not entirely comparable with those for natural gas and petroleum products in 2021.

During the publication period 2007-2020, the same integration method has been applied. Due to the loss of data on customs warehouse flows, the integration method for subsequent reporting years has been slightly adjusted. Considering this and apart from the trend breaks for specific goods flows described above, the figures can be compared easily from one year to the next.
Description quality strategy

Measures taken to maximize the quality of the data are:

• The most up-to-date source data is used.
• International trade and transport figures are converted into gross weights to facilitate integration.
• At the level of trade transactions, a check is performed on the information about gross weights and transport mode. Where necessary, data are corrected or estimated.
• The Bayesian integration method guarantees consistency of figures from the separate statistics (international trade and transport statistics). This consistency is tested and, if necessary, post-processing takes place.
• The integrated statistics also include margins around the estimates. These margins give insight into the reliability of the figures.
• The integrated figures are tested against statistics of international trade and transport, against information of the Port of Rotterdam Authority and against trade figures of neighboring countries.
• The method used and the statistical results were tested against knowledge of various experts in the field of trade, transport and logistics.