The article "Demographics and US Stock Market Fluctuations" by Carlo A. Favero and Andrea Tamoni explores how changes in the population demographics of the United States can impact stock market fluctuations. The researchers found that shifts in the age distribution of the population can have a significant effect on stock prices. Specifically, they discovered that an increase in the proportion of middle-aged individuals tends to lead to higher stock market returns, while an increase in the proportion of elderly individuals is associated with lower returns. This suggests that understanding demographic trends can help predict stock market movements.