By the end of 2011, the IIA universe consisted of more than 3,100 agreements, including more than 2,860 BITs and 330 "other IIAs" (e.g. free trade agreements or economic partnership agreements with investment provisions).

Although bilateral agreements still dominate international investment policymaking, the balance is gradually shifting from bilateral to regional treaty making, thereby increasing the impact of regions in IIA rulemaking. Regionalism can lead to simplification and growing consistency of the IIA regime. However, where new treaties do not entail the phase-out of old ones, the result can be the opposite: a multiplication of treaty layers, making the IIA network even more complex and prone to overlaps and inconsistencies.

Moreover, there are growing concerns with the investor-State dispute settlement system. Most IIAs reinforce their investment protection provisions by allowing investors directly to pursue relief through investor-State dispute settlement (ISDS). The strength of IIAs in granting protection to foreign investors has become increasingly evident through the number of ISDS cases brought over the last decade, most of which have been directed at developing countries. Host countries have faced claims of up to $114 billion and awards of up to $867 million. Added to these financial liabilities are the costs of procedures, all together putting a significant burden on defending countries and exacerbating the concerns related to policy space.

Host countries - both developed and developing - have experienced that the possibility of bringing ISDS claims can be used by foreign investors in unanticipated ways. A number of recent cases have challenged measures adopted in the public interest and policymakers in some countries have found that IIAs can unduly constrain their domestic regulatory prerogatives.

Finally, there is the growing recognition that sustainable development needs to be part and parcel of international investment policymaking.

Against this background, the IIA Section undertakes a wide range of activities related to research and policy analysis that provide cutting-edge knowledge about international investment rulemaking from a sustainable development perspective.

Among other activities, the IIA Section:

• Collects data on IIAs and investor-State dispute settlement cases

• Monitors trends in international investment policy making

• Identifies and highlights key emerging issues

The outcomes of UNCTAD's research and policy analysis on IIAs are available in the Section's publications.