On Sharia'a-Compliance and Return to Investment

In this paper we study the role of contract limitations on the performance of Islamic banks, in contrast to the role of asset limitations, invoked by Derigs and Marzban [1] to explain why Sharia’a-compliant strategies result in much lower portfolio performance than do the conventional strategies. Their results were, however, challenged in recent empirical paper by Walkshausl and Lobe [2], who argued asset limitation even sometimes, is beneficial. The reason may be that they prevent excessive risk taking by the managers. Contract limitations provide a more nuanced explanation of performance of Islamic banks, and can explain why Islamic indexes seem to underperform in emergent, rather than developed markets, as documented by Walkshausl and Lobe.