The charity wants to use this large-scale study to create a benchmark for a "well-being index" - so that the impact of future changes in policy can be measured.

BBC: Family argument

Last November Prime Minister David Cameron launched a separate "happiness index" to measure the well-being of UK citizens.

BBC: Well-being survey: Three-quarters satisfied with lives

By contrast, more than 60% of Americans fit this description, according to a Gallup-Healthways Well-Being Index last year.

WSJ: Want to Be CEO? What's Your BMI?

The information is gathered from the Bureau of Labor Statistics, C2ER, Tax-Rates.org, and Gallup-Healthways Well-Being Index.

FORBES: The Best And Worst States To Make A Living In