The national poverty level is a rate at which the average person or person is determined to survive and nothing more. Those living above this level have more than they need for basic survival, while those below this level do not have enough to survive. Historically in the United States, this rate has been tied to food costs; that is, whether or not a person’s income gives them enough money to buy food. In recent decades, this method of calculating the national (or federal) poverty level has been criticized because while food costs have dropped or stabilized overall, housing costs have risen drastically. In the 1970s, a person could expect to spend less than 25% of his or her wages on living expenses. In the 2000s, people expect to spend at least 50% of their wages on housing costs. This has financially strapped millions of Americans who are barely getting by, yet are not considered by national poverty standards to be living at or below the poverty level.