The world bank says that we shouldn't compare consumption since it is calculated differently in different countries: "Because of the diversity of methods and instruments used by the surveys, comparability across countries is limited."

http://datatopics.worldbank.org/consumption/detail

I wouldn't be surprised if the American value was grossly inflated by things like expensive healthcare and education, while the study in for example Sweden possibly didn't even count free healthcare visits, free college education, free school meals for everyone, free public transit for kids or free kindergarten as household consumption.