  Online writing lacks the non-verbal cues present in face-to-face
communication, which provide additional contextual information about the
utterance, such as the speaker's intention or affective state. To fill this
void, a number of orthographic features, such as emoticons, expressive
lengthening, and non-standard punctuation, have become popular in social media
services including Twitter and Instagram. Recently, emojis have been introduced
to social media, and are increasingly popular. This raises the question of
whether these predefined pictographic characters will come to replace earlier
orthographic methods of paralinguistic communication. In this abstract, we
attempt to shed light on this question, using a matching approach from causal
inference to test whether the adoption of emojis causes individual users to
employ fewer emoticons in their text on Twitter.
