"Marriage duration is inversely associated with spending on the engagement ring and wedding ceremony"

The whole sentence is this: "Controlling for a number of demographic and relationship characteristics, we find evidence that marriage duration is inversely associated with spending on the engagement ring and wedding ceremony." 

Note also that "weddings with a large number of attendees are likely to last longer, as are weddings accompanied by honeymoons." (Someone adds that the researchers excluded widows from the sample, which seems surprising if true.)