Impact of Global Asset Allocation Strategies

David is a seasoned wealth manager with a diverse client base that spans multiple countries. Recently, he has been analyzing the impact of global macroeconomic factors on portfolio performance. Given his recent studies, he is particularly interested in global asset allocation strategies and how they can maximize expected returns while managing risk.

David has come across three distinct asset allocation strategies based on geographical and economic integration: a fully integrated global portfolio, a regional diversification approach, and a home-country bias strategy. Each strategy offers unique benefits and challenges.

Considering the principles of global asset allocation, which of the following strategies is likely to yield the best risk-adjusted returns in the context of increasing market integration?