UNCTAD has published a report, "Investor-State Dispute Settlement and Impact on Investment Rulemaking", which considers the effect of developing investor-state jurisprudence on a "new generation" of international investment agreements. It concludes that the increase in investor-state arbitrations has influenced governments to avoid broad or imprecise provisions in favour of closely-defined terms. For example, concepts such as "investment", "fair and equitable treatment" or "indirect expropriation", the meaning of which has been considered by numerous arbitral tribunals, have been defined in more detail in more recent investment treaties, particularly those negotiated by countries in the Asia-Pacific region. Governments are also giving closer consideration to the interrelationship between the terms of the investment agreement and any applicable arbitration provisions.

The report notes that the growing legal sophistication of investment dispute resolution points to a strengthening of the rule of law at the international level that should benefit developing countries. However, the report warns that where countries are party both to older and "new generation" investment agreements, the inconsistencies between these may present challenges to developing nations.

A copy of the report is available on the UNCTAD website