Actually polygamy has never been needed in the West. The West also evolved to be free market, which means wealth for everyone who wants it. And the free market is why polygamy has never been legal.
Here's an example: America, compared to the rest of the world, was enormously wealthy. Why? It was founded on political and economic freedom, which the rest of the world wasn't.
We are no longer so much free market. Wages stopped going up in 1973, due to various reasons, but all of them involve government interference in the economy. Had wages continued to go up as they should have, the average yearly wage would be about $100,000.
Everyone who has crunched the numbers has come up with that figure: $100,000 a year.
When a man makes $100,000 a year, there is no need for a dowry. I think that's why they have never existed in the West. The closest was a woman's Hope Chest, which generally contained such things as linen.
Recently men's wages and women's have passed each other going in the opposite direction. Women's up, men's down. There are various reasons for this, but again all of them involve government interference in the economy. Look at Affirmative Action, for example, which means "White Men Need Not Apply."
For that matter, the jobs of most "educated" women (they're not educated, just schooled) are make-work.
Because men in the past made so much money (so much one man could support a wife and several kids on one salary), it also evolved that men asked the woman out, paid her way, supported her after they got married.
Those days are long gone, again, because of government interference.
Let's apply some basic supply and demand to all of this.
Since men did the asking out, the paying and the supporting, women were considered to be of high value. The men were also demonstrating they were of high value. So, many people had high self-respect because they considered themselves of high value, assigned high value to others, and others assigned high value to them. Mostly, it was a win-win situation.
That is no longer the case for both men and women.
Women who make a lot of money (many of whom have unpleasant personalities but delude themselves they are "strong" and "independent") are now considered low value by men. Yet they consider themselves high-value - in their minds. Since they cannot find men who make more money than they do, they consider most men low-value.
Let's return to dowries. When there is a shortage of men (perceived shortage, that is) dowries exist. When there is a perceived shortage of women, there are bride prices. It is evolved in the West that men paid bride prices - asking them out, paying their way, supporting them.
Bride prices can no longer be paid, although women still think they should be.
Since there is now a perceived shortage of men ("Where have all the good men gone?") it should now evolve that women pay dowries to men. Especially since educated women are now making much more than men.
This dowry should legally be non-refundable and whatever the man spends it on belongs to him under all circumstances, including divorce. If the house is in his name, it's his house. In a divorce, the children should go to him and she should have to pay "palimony."
Since women won't pay dowries they end up spinsters with cats, denying their responsibility for their predicament and blaming all their problems on men.
As outrageous as this sounds, look at what would happen. Since the average educated women would have to pay a man tens of thousands of dollars to get married, she would be a lot more careful who she married.
If she knew she'd lose kids and money to him, and had to give him money until the kids were grown, she'd be a lot more prudent (one of the Four Cardinal Virtues) in picking a man to marry.
Of course, women would be outraged at this idea, because many of them have been raised with the notion they are supposed to have all the advantages of a man and woman and none of the responsibilities.
Now we can avoid all of this by getting the government out of the economy, allowing society to repair itself.
Dowries, best of all, would force immature women to grow up.
I find all of it rather amusing. I wonder how things will evolve in the ten years? Well, maybe not evolve. "Mutate" might be a better word.