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...

Cognitive biases lead entrepreneurs to overinvest in their own companies, over exposing themselves to idiosyncratic risk. Our novel theoretical model explains entrepreneurial under-diversification by measuring the amount of potential bias in entrepreneurs' portfolio allocations brought about by...