The study looked at how people's spending habits affect stock prices in the US from 1967 to 2017. They found that changes in income don't really predict changes in stock prices on a monthly or yearly basis. People's spending is more influenced by their past spending than by their expected future income. Income and spending tend to follow patterns over time and are not random. Stock prices don't seem to be linked to changes in income, suggesting that using spending to predict stock prices might not work well. Overall, the study shows that changes in stock prices can't be reliably predicted by changes in income.