Per capita is simply the total quantity divided by the total population and doesn't tell you anything about the distribution thereof. Imagine a lord with an an

Per capita is simply the total quantity divided by the total population and doesn't tell you anything about the distribution thereof. Imagine a lord with an annual income of $100 from 10 serfs, who each pay $10 in annual rent to the lord but can sell goods at the nearby market town for an annual total of $11. The lord pays $80 for manor upkeep and luxuries to artisans etc from surrounding towns. That's $30 in disposable income, $2.73 per capita. One day the goods at the market and the artisans's fees all go up in price by 50% to $16.50 and $120 respectively. The lord then raises rent by 50% to $15. The lord now makes $150, so now his disposable income is $30 but all the serfs still have only $1.50 each of disposable income. The total of $40 and per capita of $4 went up, but the lord got most of the gains. And if the lord had the ability to raise rent more than the 50% increase to 15.50 (eg if serfs couldn't legally leave), then serfs would have no more disposable income at all while the total disposable income per capita would still increase.