The .zip file "HMBD_06.10.2022.zip"contains all country-specific computer codes and input data files created for the construction of the pooled data file provided in the Human Multiple Births Database (HMBD), as of 06/10/2022. As this is a static version of the database (as of 06/10/2022), please note that further countries or slight modifications to the code of a country already included may be implemented in the database after that date. To access the most recent version of the database, please visit https://www.twinbirths.org/en/data-metadata/ COUNTRY-SPECIFIC INPUT DATA FILES------------------------------------------------- For each country included in the database, these files gather the data found in other sources, for example in annual yearbooks or in the website of the national statistical office. All input data files are in Excel. Input data files are named with three capital letters followed by “_InputData_Metadata_dd.mm.yy.xlsx” or “_InputData_dd.mm.yy.xlsx”. dd.mm.yy. refers to the date of the most recent version available for each country, as data are updated annually. The first three letters identify the country. We use ISO alpha-3 codes for most countries; for England and Wales and Scotland we use “ENW” and “SCO”, respectively. “_InputData_dd.mm.yy.xlsx” is used for those countries for which the updated format of the metadata file is available online, as we are currently in the process of improving the metadata files of each country. In the new format, input data and metadata files for each country are provided separately. “_InputData_Metadata_dd.mm.yy.xlsx” is used for those countries for which only the old format of the metadata file is available by the time of the latest update. In the old format, input data and metadata for each country are provided in the same Excel file (sheets "input data" and "metadata - sources & notes" respectively). COUNTRY-SPECIFIC COMPUTER CODES------------------------------------------------- These files are scripts created in R (version 4.1.1.). These scripts contain the calculations performed to obtain the values for as many HMBD variables as possible, based on the input data file of each country. R-scripts are named with three capital letters followed by “_ESTIMATES” or “_Code”. The first three letters identify the country. We use ISO alpha-3 codes for most countries; for England and Wales and Scotland we use “ENW” and “SCO”, respectively. “_Code” is used for those countries for which the updated format of the metadata file is available online, as we are currently in the process of improving the metadata files of each country. “_ESTIMATES” is used for those countries for which only the old format of the metadata file is available. The R-script “Compile_data.R” compiles all estimates obtained after running each country-specific code. It generates the pooled data file available in the HMBD.