One factor that the study quantifies is human-capital endowment, meaning the brainpower created by parents, formal education and training, and on-the-job learning.
It involves comparing the interest and premiums you have actually paid on your endowment mortgage with the interest and capital repayments you would have paid on an equivalent repayment mortgage.
But as authors William Chandler and Holly Gwin explain in a recent study for the Carnegie Endowment for International Peace, China's capital markets are extremely small for a country its size.