No country's economy is static.
This statement masks a less obvious truism for statistics: the ways of measuring the economy cannot be stagnant.
They require continuous assessment and revision to take account of changes in the structure of the various sectors.
Statistics SA's recently adopted work programme for the period 2006/07 through 2008/09 details some of the planning Stats SA has introduced to take account of continuous change in the economy.
As the programme notes, economic measurement would place increased emphasis on capital formation by both the public and private sectors, which would be boosted by several major construction projects and industrial investments over the period ahead.
Government investment spending on key transport networks - road, rail and ports infrastructure - would increase markedly in 2006 and beyond.
Changing economic priorities and related changes in the structure of the economy influence the way in which the economy is measured. Gross domestic product (GDP) is the central indicator, measuring overall economic growth and growth in each sector.
In its work programme, Stats SA has prioritised a number of sectors where new or revised instruments are required for the improved measurement of GDP.
transport, where a new survey will replace the old land and freight transport survey suspended two years ago because of inadequate coverage of the sector.
The new transport survey will be one of the first of these new initiatives to come on line, with data collection scheduled to begin in November 2006.
The old land freight transport survey, last published in March 2004, collected information on total gross turnover, tonnage transported, income of commodities transported and kilometres travelled.
However, the survey gathered data only on one element of land transport, while the structure of the transport industry increasingly requires coverage of other modes of transport and related activities.
supporting and auxiliary activities, which include cargo handling, storage and warehousing, and travel agency and related activities.
Major stakeholders in the transport industry from both the public and private sectors have been involved in supplying information used in the planning of the survey and research into required coverage of the sector.
The old survey instrument measured only one part of land freight transport and as a result, data for estimation of the transport industry's short-term behaviour and consequent contribution to quarterly GDP growth were inadequate.
Additionally, the structure of the transport sector was changing, with a shift from rail to road transport, an increase in air transport and the development of a supporting and auxiliary sector.
This survey will allow users to track the behaviour of the sector on a monthly basis and will supplement information currently obtained on a quarterly and annual basis through other survey instruments.
The introduction of a new survey instrument to measure economic activity in the transport sector is a good indication of the way in which the collection of economic statistics is subject to the process of continuous improvement and necessary change.