The reserve requirement is the percentage of deposits that banks must keep in reserve and are not allowed to lend out. In the Philippines, this requirement is set by the Bangko Sentral ng Pilipinas (BSP). It is one of the tools used to control the amount of money circulating in the economy.When the BSP wants to fight inflation, it can increase the reserve requirement. This means banks have to keep more money in reserve and can lend less to customers and businesses. With fewer loans, spending decreases, and this helps slow down inflation.However, this tool also has important limitations. One major problem is that raising the reserve requirement during a crisis can create a liquidity problem. If banks are already low on cash, forcing them to hold more reserves can make things worse. They might stop lending suddenly, which can hurt businesses and consumers. This could even lead to a financial crisis if banks can’t meet the new requirements.Another limitation is that the reserve requirement is a blunt tool—it affects all banks equally, even if some are more stable than others. Also, once the requirement is raised, it is very hard to reverse without creating confusion or instability.In the Philippines, the BSP uses the reserve requirement carefully. For example, during the pandemic, the BSP lowered the reserve requirement to encourage banks to lend more and help the economy recover. But when inflation started rising again in 2022, the BSP focused more on interest rates and open market operations rather than quickly raising the reserve requirement again, to avoid shocking the financial system.In summary, the reserve requirement is a powerful but sensitive tool. It can help control inflation by reducing the money supply, but it must be used with caution to avoid hurting the banking system.