The bigger the diamond and gold-plated the reception, the less likely the marriage is to endure. That's a takeaway from Francis and Mialon's much-downloaded study of 3000. Of course, the detail is complicated.
Modest expenses and lots of people attending the reception are a big plus. Low cost and no ring and few people attending, not so good. Ring over $2000 is a risk factor. Over $20,000 spent is definitely not a plus for an enduring marriage when the woman is spending it and under $1000 is a plus if the man is spending it. Going into debt for the big day is quite a stress factor, not good. The data is presented in dense tables but the preceding discussion is easier to follow if you download the free paper.
h/t Tax Prof Blog