The article shows that when prices and wages are slow to adjust due to high costs, the impact of changes in money supply on the economy is not as strong as previously thought. This is because decision-makers prefer to make imprecise adjustments rather than incur high costs for precise changes. As a result, inflation is less responsive to short-term shocks, leading to a flatter Phillips curve. This means that as inflation decreases, the economy becomes less sensitive to changes in money supply.