WThis doctoral thesis focuses on the effects of investor sentiment on asset pricing and the challenges of portfolio optimization under parameter uncertainty. The first essay "Sentiment risk premia in the cross-section of global equity" applies a recently developed sentiment proxy to the...

We investigate the determinants of a household's decision on whether to invest in risky financial assets. Financial theory suggests that with increasing labor income risk, the reluctance of households to hold stocks increases. We propose to measure income risk as the observed variation of...