[pt] A literatura existente sobre os efeitos da Covid nos retornos das ações concentra-se em mudanças endógenas na tolerância ao risco e na modelagem de eventos raros. Até agora, essas tentativas não foram capazes de corresponder aos dados. Neste artigo, proponho uma abordagem alternativa para explicar os efeitos da Covid nos retornos de ativos em todo o mundo: separar os efeitos de longo prazo dos efeitos de curto prazo. Intuitivamente, os efeitos de longo prazo da Covid incluem disrupções nas cadeias produtivas e padrões educacionais, que, concebivelmente, levarão tempo para serem eliminados. Exatamente como acontece com os choques persistentes dos modelos de risco de longo prazo! Um modelo que permite flutuações de curto prazo e risco de longo prazo mostra que choques persistentes desempenham um papel na explicação dos retornos do mercado de ações e das taxas de câmbio em um período de tempo que começa em Janeiro de 2018 e termina em Novembro de 2021. / [en] The existing literature on the effects of Covid on stock returns focuses on endogenous changes in risk tolerance and on the modeling of rare events. So far, these attempts have not been able to match the data. In this paper, I propose an alternative approach to explaining the Covid effects on stock returns worldwide: disentangling the long-run effects from the short-run effects. Intuitively, Covid s long-run effects include disruptions of supply chains and educational patterns, which, conceivably, will take time to phase out. Exactly as it happens with the persistent shocks of long-run risks models! A model that allows for short-run fluctuations and long-run risk shows that persistent shocks play a role in explaining stock market returns and exchange rates in a time span that starts in January 2018 and ends in November 2021.

The literature investigating the relationship between stock market returns and inflation is long and has produced diverse findings. This thesis examines the nature of stock–inflation relations in Sub-Saharan countries whose stock markets were established before 1992. Evidence in this thesis shows that in the short term there is a positive relationship between stocks and inflation. Using the Johansen (1988) evidence, a long-run stock–inflation relationship is confirmed only in Nigeria and South Africa, where it is found to be negative. However, accounting for structural breaks provides evidence for a long-run relationship in Botswana, Ghana and Kenya. The evidence of the effects of regimes in the relationship is further supported by a nonparametric cointegration analysis which finds a long-run relation in countries where the Johansen (1988) method had failed. Unexpected inflation is also found to be related to stock returns in Botswana, Ghana, Kenya, Nigeria and Mauritius, which raises concerns about the use of month-end stock data in analysing this relationship. The thesis confirms the existence of hidden inflation in Kenya, Mauritius, Nigeria and Zimbabwe. Imported inflation, interest rates and the exchange rate are found to have useful information about inflation movements in Sub-Saharan Africa.