This book explores engagement between the trade and investment law regimes and the extent to which this is being driven by Preferential Trade and Investment Agreements (PTIAs). It provides an empirical analysis of engagement between the two regimes using data from 60 PTIAs and 60 Bilateral Investment Treaties concluded between 2005-2019 to see whether PTIAs result in increased engagement and whether they are doing so over time. The book explores eight of the factors identified as evidencing inter-regime engagement. These chapters look at when engagement is appropriate and to what extent it is...