As a reviewer, it is essential to do this at the offer / invitation to review stage. It is unfair in the process for everyone not to identify anything which might have an effect on your impartiality. Similarly, when writing / publishing work, all influences that might have affected your writing or the presentation of the results should be highlighted. If this is not disclosed, yet is later discovered, the negative effects for the author and their academic credibility are likely to be profound.
Dear @James Marson, many thanks for your contribution!! Would you like to extend the discussion giving some examples in your practice experience as influences that might have affected author writing or the presentation of the results?
I believe that joint work requires giving priority to the professional side over the personal side. On the other hand, there must be an understanding between researchers in order to serve the purposes of scientific research.
Authors of papers are usually required to make a statement on possible conflicts of interest in a study they are submitting.
When circumstances become a conflict of interest is tough. Some are obvious like being paid by a medical group when researching their products. Others, such a dual relationships, are a little less black and white.
Según las convenciones en Chile, se declara conflicto de interés el haber sido tutor del alumno. Si se trata de competencias entre Universidades, por ejemplo, fondos concursables nacionales, se debe declarar el conflicto de interés respecto de la institución propia y del evaluado si es la misma. También si hay disputas personales o académicas relevantes. Desde luego en Chile por Ley de Probidad Administrativa (estoy en una institución fiscal) deben declararse conflicto de intereses por lazos familiares sanguíneos o no hasta 2° grado. Haber tenido dependencia administrativa en cualquier dirección.
Dear @Cristian Garay very interesting this point of view from legislation of Chile to regarding concerns of public administration. Thank you for your contribution.