Sentiment analysis to predict the Portuguese economic sentiment based on economic news

• Autor(a) principal: Tavares, Cátia Daniela Lopes
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10071/24130
• topic: Economia -- Economy; Sentiment analysis; Economic sentiment; Sentiment indicator; Economic news; Análise de sentimento; Sentimento económico; Indicadores económicos; Notícias económicas

Measuring the economic sentiment of a country is crucial to understand and predict its short-term economic condition. This work proposes an automatic sentiment indicator, derived from collected economic news texts, that is able to accurately measure the current economic sentiment in Portugal and is highly correlated with the official Economic Sentiment Indicator, published a few weeks later by the European Commission, based on surveys. The data used in these experiments consists of almost 90 thousand Portuguese economic news, extracted from two well-known Portuguese newspapers, covering the period from 2010 to 2020. Each document was automatically classified with the corresponding sentiment polarity, using a rule-based approach that proved suitable for detecting the sentiment in Portuguese economic news. In order to perform sentiment analysis of economic news, we have also evaluated the adaptation of existing pre-trained modules and performed experiments with a set of Machine Learning approaches. Experimental results show that our rule-based approach, that uses manually written rules specific to the economic context, achieves the best results for automatically detecting the polarity of economic news, largely surpassing the other approaches. Our experimental results shows that the sentiment expressed through economic news constitute a promising way of predicting the economic sentiment, thus allowing to understand the economic situation in Portugal in almost real time. The developed indicator, based on the news, give us a predictive power of the economic fluctuations and the sentiment concerning the economic agents about the present and the future of the economy.