The depth index is a simple additive index of 7 key statements that can be part of a PTA.
The 7 key statements are tariff reduction, intellectual property rights protection, government purchases, technical barriers to trade, services, investments and compe-tition. The scale of the index is 0 – 7. The depth measure used here was developed by
Dür, Baccini, and Elsig (2014).
The depth of PTAs is heterogeneous. Some PTAs cover a large number of different issues, from trade in services to government purchases, whereas others are very narrow. Some PTAs include far-reaching statements, while others are relatively shallow.
For example, a PTA with a depth score of 0 is an agreement with no substantive statements in any of the 7 key statements. On the other extreme, a PTA with a depth score of 7 is more than an agreement with substantive statements in all 7 key statements.
Further details on the index are provided in
Table 1.
Note that the depth index is not available (N.A.) for all PTAs because the researchers did not find full texts for all agreements.