**4. Conclusions**

The potential for a hold-up problem is an important challenge in the international natural gas trade. As discussed above, multiple significantly large supply disruptions in the last two decades illustrate this importance. The reasons for this importance are because (1) gas pipelines are expensive and asset-specific investments; (2) international gas trade might include more than two parties to a transaction due to the presence of transit countries. The hold-up problem is thus crucial for landlocked countries. As discussed above, gas supply disruptions due to issues related to transit countries happened quite frequently in the last two decades.

The contribution of this paper is filling the gap in the literature, which rarely discusses the issues related to transit countries, despite their relative importance. Additionally, this paper also suggests three ways to ameliorate the issues related to transit countries: (1) use of an international organisation; (2) designing contracts with price mechanisms that might reduce the possibility of disputes; (3) reducing the number of parties involved in the trade.

Future research on the hold-up problem in natural gas might go along two routes. First, theoretical studies of the cost of a hold-up as a function of relevant factors. Second, empirical studies to test these theoretical studies. A better understanding of the factors affecting hold-ups might be enormously beneficial to avoiding them.

**Author Contributions:** Conceptualisation, G.N. and T.K.; methodology, G.N. and T.K.; investigation, G.N. and I.T.; resources: G.N. and I.T.; writing—original draft preparation, G.N. and I.T.; writing review and editing, G.N. and T.K.; visualisation, G.N. and T.K.; project administration, G.N. and T.K. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Data Availability Statement:** The data are given in the paper. There is no other data to be provided separately.

**Conflicts of Interest:** Authors declare no conflict of interest.
