Campaign resources and pre-electoral coalitions

Why do parties form pre-electoral coalitions (PECs) in executive elections? The party of the executive candidate may welcome coalition partners because of the votes that they can deliver. However, PECs often include parties that bring few votes to the coalition. I theorize that parties with a candidate in the executive election welcome small parties because of the campaign resources that they bring to the PEC. I test this argument using data from mayoral elections in Brazil, where parties do not control access to advertisement on radio/TV. The results indicate that campaign resources increase the likelihood of being admitted to a PEC when the party without an executive candidate has few votes to offer.