Complex sentence: A growth rate of unemployment below the natural rate of growth leads to an increase in the rate of inflation--but a growth rate of unemployment above the natural rate of growth leads to a decrease in the rate of inflation, also known as disinflation.
Split into simpler sentences: A growth rate of unemployment below the natural rate of growth leads to an increase in the rate of inflation. But a growth rate of unemployment above the natural rate of growth leads to a decrease in the rate of inflation, also known as disinflation.