In many states of the United States, the police cannot force a person to identify himself, or show ID, unless the police officer has reasonable suspicion that the person in question has committed a crime, or is about to commit a crime (in which case the police can either detain or outright arrest that person based on that suspicion of a crime, and demand identification.) If the person in question has not committed a crime, and especially if the police officer cannot name such a crime, in these states the person can lawfully refuse to identify himself or show ID.
Finnish law, however, states that if a police officer orders a citizen to show ID (or if not carrying any, identify himself by name and social security number), then said citizen must comply. There's no requirement for the person having committed a crime, or even being suspected of such. Basically, if the police orders you to identify yourself, you have to do it, by law.
The same law likewise states that any lawful command given by a police officer must be followed. (For example, if a police officer orders you to leave a space, even if it's a public space, or move away, or stay where you are, or other similar things, you are compelled by law to do so.)
Deliberate failure to do any of the above may result in being fined, or even jailed, for insubordination. I do not know how this goes in the United States.
(As a side note, this "insubordination" is one of the lowest forms of resisting a police officer, and there are of course much graver ones, like for example resisting arrest, violently resisting arrest, assaulting a police officer, and so on. In the Finnish judicial system if tried of such a crime, charges are not "piled up", and you will only be sentenced for the worst crime of the bunch. In other words, if you for example resist arrest, you will be sentenced for that, but not for insubordination, even though technically speaking you are also guilty of that. In general, you are sentenced only for the "biggest" crime you committed, not any of the "lower" ones, even if they fill the criteria of what you did.)
The Finnish law kind of assumes that the police will never abuse their power, and that every command that the police gives to private citizens is necessary and for the benefit and protection of everybody involved.
Luckily Finland has one of the least corrupt police forces in the world. Police misconduct and abuse is very rare. There have been cases, of course, but they are extraordinarily rare.
I suppose that limiting the powers of the police makes more sense in the United States. While the vast majority of police officers there might be completely professional and always conduct themselves properly, there's always that small minority, which is still too large, that will happily abuse their power to bully and intimidate people. Even if 99.9% of police officers are completely ok, that 0.1% is still too large of a group. It is, after all, much more common to see genuine cases of abuse from police in the United States than it is in many other countries, such as Finland.