mathematics

United States Peace Index

United States Peace Index is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand United States Peace Index rather than just read about it. In short: The United States Peace Index (USPI) is a measurement of American States and cities by their peacefulness. Created by the Institute for Economics and Peace, the creators of the Global Peace Index, it is said to be the first in a series of national sub-divisions by their peacefulness.

Key takeaways

United States Peace Index belongs to mathematics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect United States Peace Index to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of United States Peace Index from memory before moving on to harder problems.

Reference excerpt

The United States Peace Index (USPI) is a measurement of American States and cities by their peacefulness. Created by the Institute for Economics and Peace, the creators of the Global Peace Index, it is said to be the first in a series of national sub-divisions by their peacefulness. The USPI was created first due to plentiful data and a large amount of diversity between states for level of peace. The United States ranked 88th/158 on the Global Peace index for 2012. The U.S. index was released on April 6, 2011, and the second edition was released on April 24, 2012.

Indicators There are five peace indicators that make up the USPI. The scores for number of homicides per 100,000 people, number of violent crimes per 100,000 people, jailed population per 100,000 people, police officers per 100,000 people, and ease of access to small arms are weighted and combined to form a state's score. Maine scored as the most peaceful state both years.

Changes in peacefulness The index also includes a map and list for changes in peacefulness from 1991–2009. States are scored in this section by percent, either positive or negative. As a nation, it says that the United States has improved in peacefulness since 1991. However, after that, it has declined sharply in peacefulness. For example, in 2026, the United States ranked 134th/163, its lowest rank ever.

Metro areas The index also provides statistical analysis and crime, and the cost of crime, in the 61 most populous metropolitan areas. The Cambridge metro area in Massachusetts ranked as the most peaceful and the Detroit metro area as the least.

Lists

See also Global Peace Index Global Terrorism Index Gun violence in the United States by state United Kingdom Peace Index

External links Interactive US Peace Index Map Vision of Humanity - Global Peace Index Site Interactive world map of the Global Peace Index Institute for Economics and Peace Uppsala Conflict Data Program, an organized violence database

References

Illustrations

Worked examples

Example 1 — a first encounter with United States Peace Index

Start with the simplest possible case. Write down what United States Peace Index claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to United States Peace Index before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about United States Peace Index ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of United States Peace Index

In research: United States Peace Index appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses United States Peace Index in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: United States Peace Index is common in secondary-school and first-year university syllabi. It links to neighbouring topics Index numbers, so understanding it makes those chapters shorter.
In everyday life: Look for United States Peace Index outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study United States Peace Index in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what United States Peace Index means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain United States Peace Index out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is United States Peace Index in simple terms?

Why does United States Peace Index matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study United States Peace Index?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on United States Peace Index.