This question asks "which laws apply" and this answer talks about "who has jurisdiction."
Reading that led me to wonder if they are necessarily the same statement.
Are they?
Or, are there cases where an authority generally able to hear/prosecute cases on a particular subject/law does not have jurisdiction, and an authority who does have jurisdiction has to apply laws that don't strictly match the venue where the authority sits/covers?
Federal courts interpreting state law jump to mind, but I'm not sure if that example really answers this question.
2 Answers
No they are not the same statement.
Who has jurisdiction?
Let's disentangle a few things:
A jurisdiction is an entity that has sovereignty to make, interpret and enforce its own laws. Each country in the world is a jurisdiction. Sub-national entities like states, provinces and municipalities may be a jurisdiction depending on the operation of law in the country they are part of. Some supra-national bodies like the EU and the UN are jurisdictions. To some extent, even companies, clubs and similar bodies are jurisdictions to the extent that they can make, interpret and enforce its own rules.
A jurisdiction can decide that it has jurisdiction based on a whole raft of matters including:
- where the event took place
- where the party(s) are resident
- where the party(s) are citizens
- registration of things like planes, trains and automobiles
- if money passed through their financial system
- etc.
A court or tribunal has jurisdiction if the jurisdiction has jurisdiction and it is the correct body within its jurisdiction to hear a particular matter.
Which laws apply?
Once a court or tribunal has decided that it does have jurisdiction it then needs to know what law to apply. This may be the law of their jurisdiction or another jurisdiction or both.
Example
For example, imagine there is a company in New York, USA that sells a product to a consumer in New South Wales, Australia. Further suppose that the contract says it will be governed by the laws of Ontario, Canada (don't ask me why).
In the event of dispute, let's say the consumer begins proceedings in the Local Court in New South Wales. The New York company petitions the court to say that the correct forum is the court in Ontario, or New York, or Mexico where the product shipped from but certainly not New South Wales.
The court in New South Wales will consider the jurisdictional arguments and decide if it does or does not have jurisdiction. If it decides that it doesn't then the customer would have to bring an action somewhere else (where the process repeats). Worth noting that the New York company would be precluded from arguing in that forum that New South Wales was the right jurisdiction because they can't have their cake ...
If it decides that it does have jurisdiction then it would consider what law applies. Its quite probable that they would accept that the contract is governed by Quebec law. However, Australian law, most specifically the Australian Consumer Law would also apply. If there was a claim on a tortuous basis this might be New South Wales or New York law. They would then proceed to decide the case on the applicable law including working out how to reconcile any incompatibilities.
The question of jurisdiction and the question of choice of law are two different issues.
A sample example, two companies enter a contract stating it is to be interpreted under California law and that all disputes arising from the contract are to be settled in Manhattan.
A more complicated example:
Aircraft Manufacturer is located in Omaha and incorporated in DE. Plane crashes in NC. Lawsuit is filed in DE. What law applies? (A tough question with major implications.)
A simpler example but real example with stranger results:
P is injured in a Hilton Hotel in London. P sues Hilton in NYC for injuries. (English law probably applies.)