When are signals complements or substitutes?

Tilman Börgers, Ángel Hernando-Veciana, Daniel Krähmer. When are signals complements or substitutes?. J. Economic Theory, 148(1):165-195, 2013. [doi]

@article{BorgersHK13,
  title = {When are signals complements or substitutes?},
  author = {Tilman Börgers and Ángel Hernando-Veciana and Daniel Krähmer},
  year = {2013},
  doi = {10.1016/j.jet.2012.12.012},
  url = {http://dx.doi.org/10.1016/j.jet.2012.12.012},
  researchr = {https://researchr.org/publication/BorgersHK13},
  cites = {0},
  citedby = {0},
  journal = {J. Economic Theory},
  volume = {148},
  number = {1},
  pages = {165-195},
}