İt's an assumption made that the data given by such bodies are reliable because of their economies of scale comparative advantage compared to other organizations, but definitely there is also chance for bias in as much as the data is trusted to be reliable

A lot of problems arise from the user who does not check the metadata. discontinuities will also be set out on the database. If these are ignored it is no surprise that mistakes are made. If anything is not clear, one could consult the National Statistical Office or Central Bank. These supply the data and generally have someone monitoring the data.

Strengthening source data, especially in develping countries will go a long way into improving the quality and accuracy of data.

My two cents: First, data published by IMF and WB are those provided by national authorities and reflect, inter alia, the quality of the underlying national statistics. Second, the data published must follow international standards in order to be comparable with other countries. Here, you may find some discrepancies with the national publications when the local administration uses different definitions.

Sometimes, national governments keep using older definitions, that may not follow international standards anymore. This is often the case for monetary and fiscal aggregates. And if the IMF stops publishing some data (e.g., inflation in Argentine a few years ago), which is something that very rarely occur, it means they really don’t trust the national figure and you better take notice.

It is always assumed that data provided by international organisations like IMF and World Bank is always accurate and reliable.If there is any discrepancy in data given by IMF and World Bank,it is due to their respective functions and purposes.The IMF overseas the stability of world's monetary system,while the goal of World Bank is to reduce the poverty . byo providing