It's not the median, but the marginal cost to advance to the next level.
Again, the marginal cost to advance to the "next level" can only increase if more people are able to achieve it. "Keeping up with the joneses" is a zero sum game.
Also, if we are talking about "keeping up with the joneses", then it's irrelevant to focus on income or wealth. We should focus on consumption - interestingly, consumption inequalities are lower than both income and wealth inequalities.
Again, the marginal cost to advance to the "next level" can only increase if more people are able to achieve it. "Keeping up with the joneses" is a zero sum game.
Also, if we are talking about "keeping up with the joneses", then it's irrelevant to focus on income or wealth. We should focus on consumption - interestingly, consumption inequalities are lower than both income and wealth inequalities.