Trading up for a younger wife is a practice that men are sometimes accused of using divorce to accomplish. In reality, it more often happens when divorce is forced upon a man by a wife who imagines she is getting her ultimate revenge by dumping him (as well as perhaps "trading up" to a better husband by branch swinging). In many instances, his sexual market value will have increased since his first marriage, and he may also have learned from the mistakes he made in choosing the woman who divorced him. Therefore, he may be in a position to "trade up" to a significantly better new wife, even though he would have preferred to keep the original family together.
Divorced men in their 40s, 50s, or 60s will often resort to a foreign woman as their most feasible opportunity to marrying a girl in her early 20s, and find that she also has a much better personality than a typical American woman.
Heartiste notes one reason why men who married a woman in her 20s rarely feel the need to trade up for a younger wife:
Now, naturally, if you marry an under-30 woman, the day will come, ostensibly, that she’ll be your over-30 wife. But you’ll have something that chagrined men who married women on the cusp of sagging cups don’t have: Years of very fond, very monopolized, very supple memories. If you maritally snag a 21-year-old minx and occupy her sugar walls for the next ten years, the spermatomically bonded cervix-splattered glue of all those splendid tumbles of passion accrue into something larger than the sum of your individuated speckles. All that young woman heat, heat which will never be replicated with the older version of your wife, captures into limbic amber a network of interlocked, superconductive emotions with the power to sustain lovingrapture a good ways past the poignantly brief era of peak wife ripeness, onward into the elevator muzak era of bland marital inertia (50 years, plus or minus).