All data in this chart – except for Spain – is based on our database here at @OurWorldInData.
For 2 reasons this tweet led to some confusion on social media and the press:
[While his tweet was not clear, the sources in the footer of the OECD chart are clear.]
We aim to not to include antibody tests, but the OECD summed up PCR and antibody tests for Spain.
[1,035,522 PCR tests + 310,038 antibody tests according to their source.]
They referred to him as ‘uno de los expertos que elaboran los informes de la OCDE’.
El País now corrected it, but others quoted their mistake.
From that I hope it is clear that we make a huge effort to carefully explain what can and cannot be interpreted from the data country by country.