"Long-term interest rates" are an important concept in the economy and financial markets, and they are a key factor of interest for investors and policymakers. Long-term interest rates indicate the interest rate for borrowing or lending funds over future periods. Long-term interest rates are influenced by various factors, but among them, the following three concepts are crucial:

1. Federal Funds Rate (FF Rate): The FF Rate is a short-term interest rate set by the United States' central bank, the Federal Reserve. The FF Rate is typically one of the primary tools used by the Federal Reserve to adjust monetary policy in response to economic conditions and inflation. Generally, when the FF Rate rises, there is a tendency for long-term interest rates to also increase.

2. Inflation Rate: The inflation rate is an indicator of the rate at which prices of goods and services are rising. When inflation rates are high, there is a potential for future devaluation of currency values, prompting investors to seek higher interest rates. Therefore, high inflation rates can be a factor that pushes up long-term interest rates.

3. Potential Growth Rate: The potential growth rate refers to the long-term growth potential of an economy. When an economy has a high potential growth rate, expectations for corporate earnings growth tend to increase, and this can lead to higher long-term interest rates. Conversely, when potential growth is low, long-term interest rates may decrease.

These factors interact when determining long-term interest rates. For example, when the central bank raises the FF Rate, there is typically a corresponding increase in long-term interest rates. Similarly, expectations of high inflation or strong potential growth can drive long-term interest rates higher. Financial market participants consider these factors when predicting future interest rate trends and making decisions regarding investments and economic policies.

Long-term interest rates can vary by country or region, and they fluctuate in line with each region's economic conditions and monetary policies. Understanding the soundness of an economy and future interest rate trends requires a careful analysis of these factors.