Q:

Do small dogs live longer than large dogs?

I thought small dogs lived longer than large dogs, then I stumbled on this answer about heart beats and longevity.
In the following table:

Large dogs are said to live longer than small dogs. Which is contrary to some beliefs, like in this article.
So who is right?

A:

Yes, small dog breeds tend to live longer than larger breeds.

Longevity of British breeds of dog and its relationships with sex, size, cardiovascular variables and disease: 

smaller dogs had longer lifespans.

Statistical analysis regarding the effects of height and weight on life span of the domestic dog:

A negative correlation was observed between height and longevity (r = −0.603, p < 0.05), and between weight and longevity (r = −0.679, p < 0.05). Weight was the significant predictor of life span (p < 0.001), revealing that breeds smaller by weight generally live longer than heavier breeds.

Do large dogs die young?

In most animal taxa, longevity increases with body size across species, as predicted by the oxidative stress theory of aging. In contrast, in within-species comparisons of mammals and especially domestic dogs (e.g. Patronek et al., '97; Michell, '99; Egenvall et al., 2000; Speakman et al., 2003), longevity decreases with body size.

