Young Americans believe they have the best health in the world...

Louie

Of course, it turns out they're actually last among developed nations in real health outcomes.

The U.S. ranks #1 among 17 affluent, western countries in the percentage of people aged 5 to 34 who rate their health as good. Unfortunately, when doctors look at people’s actual health, at indicators such as obesity, diabetes, and simply the chance that someone will die before his or her next birthday, the U.S. ranks last: young Americans are #17 out of 17 in real health.

Of course, it turns out they're actually last among developed nations in real health outcomes.

The U.S. ranks #1 among 17 affluent, western countries in the percentage of people aged 5 to 34 who rate their health as good. Unfortunately, when doctors look at people’s actual health, at indicators such as obesity, diabetes, and simply the chance that someone will die before his or her next birthday, the U.S. ranks last: young Americans are #17 out of 17 in real health.

Like the implication that the lack of gun control contributes to lower life expectancies

The US has a murder rate about four times that of the UK.. If as a rough approximation half of that is due to gun control issues, that would correspond to an extra around 6,000 deaths yearly. Around 2.5 million people die in the US yearly. Victims of violent death are much more likely to be young but even if one assumes that the additional deaths are all infants, that's on the order of 3 months less of life. Even if one assumes that all differences in murder rate are due to gun control differences, the difference is still less than a year. It seems like the actual value that gun control is probably impacting is on the order of a month or so. So the conclusion that this isn't a substantial effect seems correct.

Incorrect. You're comparing apples to oranges. The UK only counts as murders or homicides those crimes which have a conviction; the US counts all deaths which are ruled a homicide. Additionally, the UK counts homicides as occurring when the trial is complete; a murder today may not be counted until 2016, and will be included in the 2016 statistics.

The correct proportion is probably somewhere around 33% or 75% - that is, the US homicide rate is about 33% higher than the UK homicide rate. But given the large number of deaths in the UK with an uncoded cause of death, the homicide rate could very easily be equivalent.