**2. Case Studies**

In presence of hold-up potential, there is a trade-off between an immediate opportunistic gain and a long-term cooperation gain. Below are several case studies where hold-up took place, involving some of the largest exporters of natural gas over the last few decades. The supply disruptions discussed below were often mainly initiated by the exporter, and sometimes by a transit country.

The exporters discussed below include Algeria, Indonesia, Russia and Turkmenistan. The selection criteria for the case study countries is the combination of the volume of natural gas exports and the availability of public information on their contractual performance. This study omits some large natural gas exporters, such as Qatar, due to a lack of publicly available information on opportunistic behaviour. Future research into Qatar's experience might illustrate strategies that promote cooperation between trade partners, for example, amicable nationalisation of the world's largest gas field in the late 1970s, and repeated forgiveness of take-or-pay penalty [19,20].

### *2.1. Algeria*

Algeria has the 11th largest natural gas reserves in the world, at 4.5 Tcm (trillion cubic meters) (EIA, 2019). Over 70% of its gas exports go to Italy, Spain, France, and Turkey [21]. Algeria has acted opportunistically several times, involving contractual breakdowns, interrupted supplies, and unexpected price changes. This opportunistic behaviour was often associated with significant changes in market prices. The following paragraphs present the details of some instances of opportunistic behaviour.
