Your Top 5 questions about World Bank Open Data


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When the World Bank opened its doors and launched the Open Data Initiative two years ago, our Data Help Desk was flooded with questions, requests and comments from students, researchers, journalists, economists, statisticians and more. The demand for our data has only grown, and right now, our team answers around a thousand data-related queries a month by email and phone.

Meet the World Bank Open Data Helpdesk Team


This growing appetite for data keeps us on our toes: the Open Data team is constantly on the lookout for new data and sources; validating, compiling and curating data; designing tools to make data more usable - all the while answering your questions and using your feedback to improve our products.

If you ever wondered whether you’re the only one asking us about where to find historic country classifications, where to find GDP figures for the former Soviet Union or how to calculate changes in base year - the answer is - no, you are not alone. Every day dozens of users from around the globe contact us in search of answers to these and many other questions.

Following Tariq’s “Top 5 Ways to Access World Bank Data”, we decided to list the top 5 questions that we get asked at the Open Data helpdesk.

So, here we go, in no particular order:

1. How do you classify countries?

You can read a more complete answer here, but to summarize:

By income per capita
Our main classification criterion is gross national income (GNI) per capita. Based on its GNI per capita, every country is classified as low income, middle income (subdivided into lower middle and upper middle), or high income. These classifications get revised every year as of July 1st.

By Geographic region
Classifying countries geographically may seem straightforward, but it does occasionally need some extra explanation . For example, Djibouti while being a Sub Saharan African country, is classified under Middle East and North Africa (MENA), and Iran, which under the United Nations classification is listed under South Asia, the World Bank also classifies as MENA.

These regional aggregates and geographic regions are primarily for operational and administrative purposes, and since some countries do not have World Bank country offices, they are added to a neighboring country which could be a part of a different region.

Historical Income Classification
While there are pages we have on the site that list all the different income classifications, like the Country and Lending Groups Page, it’s often the historical data that the users are after. We actually have that too, and you can find it at the bottom of the Short History Page as an Excel spreadsheet.

2. How many times are the data revised or updated - and when?

Our statisticians and data quality experts work diligently to make sure that our data is as accurate as possible. Data in the World Development Indicators database comes from multiple sources, including  agencies such as the United Nations and World Health Organization, and national statistical agencies in countries around the world.

We normally update World Development Indicators 4 times a year in April, July, September and December. Other datasets may be updated more or less frequently and information on update cycle scan be found in the Data catalog entries for each dataset.


We also publish a data updates and errata page to document major changes or revisions to previously published data.

3. Can I get GNI per capita (or any other indicator data) for a particular set of countries for certain years?

Sure you can. The best way to retrieve this data would be to use one of our data tools, like the indicator pages on the data site, which also has simple navigation to data by country or topic. For those comfortable with performing customized queries, the DataBank  tool lets you create your own queries, generate tables, charts and maps and easily save, embed and share them.

We’ve also made a DataBank tutorial video and prepared some FAQs and instructions.  If you’ve got any more questions, just contact us at [email protected] – we’re always here to help.

4. Can you change the base year for the constant series and send me the data for say “Final consumption expenditure (constant 2000 US$)” with a different base year?

It’s actually pretty easy to do this yourself – you can find the information in the “About the Data” page. The explanation tells you how to rescale the 2000 base year to 1995, but the same procedure applies to adjusting the base year to any other year.

5. We would like to republish your data in our research/publication/website – whom should we contact and how much does it cost?

We encourage you to use our data in creative ways; all datasets listed in our data catalog (unless specifically noted) are covered by our terms of use.  Provided you follow them, you don’t need to contact anyone or sign any contracts. They permit free commercial and non-commercial use and re-use of our data, provided they are correctly attributed.  You can read the detailed version here.

So, these are the Top-5 questions that get asked by our open data users, look out for more soon!


Maryna Taran

Development Data Consultant

Federico Escaler

Development Data Consultant

Join the Conversation

JJ Tan
July 18, 2012

Thanks for a very helpful list of resources and instructions on how to use World Bank data. It might also be useful to mention in this post that there's an API available for developers to access the data :-)

Azita Amjadi
June 29, 2012

Dear Roos,

The data for average precipitation,, were collected every 5 years prior to 2007. Therefore, it is only available for the years 1992, 1997, 2002, 2007, 2008, and 2009. Unfortunately, this indicator is not available on a quarterly basis. The original source of the data is Food and Agriculture Organization, electronic files and web site and we would suggest contacting them directly to find out more about this specific indicator.
On quarterly data, unfortunately the World Development Indicators database provides only annual data. For this type of information we would suggest contacting country statistical offices as they may collect more granular data. For poverty headcount ratios, the data only dates back to 1990. on your last question, GDP does not include any aid data. We hope this helps.


Azita Amjadi
July 10, 2012

We have data on income shares from 2000-2011, but not as complete time-series. If you provide us with your e-mail, we can send you an Excel file with available data on income shares.
Percentage share of income or consumption is the share that accrues to subgroups of population indicated by deciles or quintiles. The source of this data is World Bank, Development Research Group. Data are based on primary household survey data obtained from government statistical agencies and World Bank country departments. Data for high-income economies are from the Luxembourg Income Study database. For more information and methodology, please see PovcalNet (


July 17, 2012

Hello, sorry to bother you.

I would like to know how do you compute the GINI index? I have the gdp per capita of chinese provinces and I have tried both using STATA and Excel, but I couldn't get anything close to your report's results.

I will really appreciate even if you give me an advice. Thank you in advance.

Best regards,


Azita Amjadi
July 27, 2012

The GINI index estimates we publish are computed based on income or consumption data measured from household surveys; not based on sub-national GDP data.
Access for more details about our methods, to replicate our results and to access the underlying data.

Note this is clearly documented in the WDI print edition, but not all that metadata makes it to our on-line database nor to our API. But to get more information, click on "Notes" icon while using the DataBank data retrieval system accessible from….

Hope this helps.

Roos Bouman
June 29, 2012

Dear Ms/Mr,
At the moment, I am writing my bachelor thesis and I am thankfully using your data for a part of the empirical research. I do however have some questions:

1) There is data on the average rainfall in Somalia but do you also have yearly (or even better: quarterly) data of the rainfall between 1990 and 2010? It seems to me like you do, as there is an option to show the average rainfall in exactly those years.

2) The data that I found on Kenya and Somalia is on a yearly basis. Is it also possible to have quarterly based data? I need this for:
- GDP per capita (current US$) in Kenya
- Inflation in Kenya
- The refugee population by country of asylum for Kenya
- Total employment to population ratio (15+) for Kenya
- The refugee population by country of origin for Somalia
- The battle-related deaths for Somalia
- And the IDP high estimate for Somalia

3) Do you have any data on the headcount ratio in Kenya between 1990 and 2010?

4) Does the data on Kenyan GDP (current US$) include aid reveived and other development assistance?

Thank you for helping me.
Best regards,
Roos Bouman

Robert Murray
July 07, 2012

I'm trying to form the ratios of income accumulated by the highest 10%-tile, lowest 10%-tile, and median (or third 20%-tile) for each of the nations of the world, especially the G20.

Your tables for the highest 10% and lowest 10%, and third 20%-tile would work, except there is no data for the larger countries (e.g. USA).

Can you help me, either in your database, or others you know of?


Hal Z Zhao
July 07, 2012

Indeed very helpful resources.

Tim Herzog
August 27, 2012

David: apologies, for the broken link. I fixed it in the original comment above.

August 22, 2012

Thank you very much. However, sorry to bother you again but the link is not working, could you help me?

One last question, am i wrong or you do not have published GDP data at province level for China? If I am not wrong, is there a way to get these data?

Thanks in advance for your answer. You are very helpful.

Jale Jale
March 11, 2014

Hello, I accessed you Government Bond Yield Spreads data. I needed it for my dissertation and the numbers helped me a lot. However, I wanted to make sure which sources you used - i.e. which banks and agencies did you take the rates from (like itigroup, Merril Lynch, Datastream, Thomson Reuters). I sent you an e-mail as well, but wanted to try here as well, as it seems you answer very quickly.

April 24, 2014

Dear Maryna & Federico,
I would like to know whether it is possible to get the household expenditure data in current US dollars also on a quarterly basis? ATM, the website only publishes the annual results.

May 06, 2014

Hi Daliana,
Please email us at [email protected]. Our team of specialists will get back to you on where you can find the data. Unfortunately, WDI only publishes annual data at the country level. Please do send us an email and we will direct you to where you can find your data. Many Thanks.