Long-term borrowing costs have been decreasing for decades, affecting asset values and government finances. A study looked at factors influencing this trend and found that slower growth and population age play a big role. Global influences also contribute to the decline. The US natural interest rate has risen recently due to fiscal stimulus. The study focused on ten-year borrowing costs instead of short-term rates, showing that US monetary policy may not be as tight as it seems, explaining the economy's resilience post-pandemic.