In order to decide whether a rule is self-executing or not, one must only look at the rule in question. National traditions do not count. A rule that says that states should guarantee freedom of expression to its citizens is self-executing. A rule that says that states should take all the necessary measures to create enough employment is not. Non-self-executing rules of international law only impose the obligation on states to take measures and to create or alter legislation. Citizens or national judges cannot invoke these rules (and demand employment as in the previous example) in a national court. This means that international law that is not self-executing must be transformed into national law.
The priority of international law remains a fact, whether this law is or is not self-executing. A state cannot invoke its national law as a reason not to respect its international obligations. In case of non-self-executing rules, it is obliged to change its national law or to take certain measures. It violates international law if it does not do so. In this case, a national judge can only decide that her state should modify national law or take certain measures. She cannot invalidate national law that contradicts non-self-executing international law. She can only declare national law null and void if it contradicts self-executing international rights.
Most human rights contained in the main human rights treaties are self-executing and can be invoked by individuals in a national courtroom, although this is the case more for civil rights than for economic and social rights.