This paper conducts an empirical examination of the determinants of the ten-, five- and one-year Portuguese government bond yields by performing a time series econometric analysis for the period between the first quarter of 2000 and the last quarter of 2016. The literature suggests that the evolution of government bond yields depends on three main risk drivers, namely credit risk, global risk aversion and liquidity risk. We estimate three equations for the ten-, five- and one-year Portuguese government bond yields, including eight independent variables (macroeconomic performance, fiscal conditions, foreign borrowing, the inflation rate, labour productivity, the demographic situation, global risk aversion and liquidity risk) to take into account all three risk drivers referred to in the literature. Our results show that there are no significant differences in the determinants of the Portuguese government bond yields among the different maturities, either in the long term or in the short term. Our results also confirm that all three of the risk drivers have exerted a strong influence on the evolution of the Portuguese government bond yields. Liquidity risk, the inflation rate and foreign borrowing are the main triggers of the rise in the Portuguese government bond yields, which does not counterweigh the beneficial effects played by the fiscal conditions, demographic situation and labour productivity. ; FCT
This paper makes an empirical analysis of the evolution of Portuguese government bonds yields in order to identify their main determinants for the period between 2000 and 2016 using quarterly data. An equation of the Portuguese government bonds yields is estimated considering three different maturities (one, five and ten years) and including eight independent variables (GDP, public debt, external debt, labour productivity, activity rate, inflation rate, stock market volatility and liquidity) to capture the global effects of credit risk, global risk aversion and the liquidity risk. Our main findings were that GDP growth rate, external debt, inflation rate and liquidity exert a positive effect on the ten year maturity sovereign bond yields while public debt, labour productivity, activity rate and the stock market volatility affect negatively the yields. Evidence supporting the contradictory sign of what the majority of the literature claims regarding public debt is also found. Overall, the results point out that there are no significant differences regarding the determinants of the government bonds yields for the different maturities. Finally, we conclude that the yields were harmful affected by liquidity, labour productivity but mostly by external debt. In turn, activity rate, GDP, public debt and mostly the inflation rate had a beneficial effect on the Portuguese government bonds yields. ; Esta dissertação faz uma análise empírica à evolução das yields da divida pública portuguesa, procurando identificar os seus principais determinantes, para o período entre 2000 e 2016 usando dados trimestrais. Foi estimada uma equação para as yields da divida pública portuguesa considerando três maturidades distintas (um, cinco e dez anos) e incluindo oito variáveis independentes (PIB, divida pública, divida externa, produtividade do trabalho, taxa de atividade, taxa de inflação, volatilidade do mercado acionista e liquidez) de modo a capturar de forma global os efeitos do risco de crédito, da aversão global ao risco bem como do risco de liquidez. Os resultados demonstraram que o PIB, a divida externa, a taxa de inflação e a liquidez influenciam positivamente as yields da divida pública com maturidade a dez anos enquanto que a divida pública, a produtividade do trabalho, a taxa de atividade e a volatilidade do mercado acionista afetam negativamente as yields. Foram ainda encontradas evidências que apoiam o sinal contraditório ao que a maioria da literatura afirma relativamente à divida pública. No GERAL, os resultados apontam que não existem grandes diferenças nos determinantes para as diferentes maturidades. Finalmente, concluímos que a liquidez, a produtividade do trabalho, mas sobretudo a divida externa foram os fatores que originaram uma subida das yields, enquanto que a taxa de atividade, o PIB, a divida pública e a inflação revelaram ter um efeito benéfico sobre as yields da divida pública portuguesa.
