An economy is initially in macroeconomic equilibrium, with the relationships between sectors governed by the circular flow of income model shown below.
If the economy experiences simultaneous changes in its injections and leakages (withdrawals), which of the following scenarios must result in a net contraction of national income (YYY)?
ΔI=+£8bn\Delta I = +\pounds 8\text{bn}ΔI=+£8bn, ΔG=−£12bn\Delta G = -\pounds 12\text{bn}ΔG=−£12bn, ΔX=+£5bn\Delta X = +\pounds 5\text{bn}ΔX=+£5bn and ΔS=+£4bn\Delta S = +\pounds 4\text{bn}ΔS=+£4bn, ΔT=−£2bn\Delta T = -\pounds 2\text{bn}ΔT=−£2bn, ΔM=+£1bn\Delta M = +\pounds 1\text{bn}ΔM=+£1bn
ΔI=−£5bn\Delta I = -\pounds 5\text{bn}ΔI=−£5bn, ΔG=+£15bn\Delta G = +\pounds 15\text{bn}ΔG=+£15bn, ΔX=−£2bn\Delta X = -\pounds 2\text{bn}ΔX=−£2bn and ΔS=+£3bn\Delta S = +\pounds 3\text{bn}ΔS=+£3bn, ΔT=+£6bn\Delta T = +\pounds 6\text{bn}ΔT=+£6bn, ΔM=−£3bn\Delta M = -\pounds 3\text{bn}ΔM=−£3bn
ΔI=+£10bn\Delta I = +\pounds 10\text{bn}ΔI=+£10bn, ΔG=−£4bn\Delta G = -\pounds 4\text{bn}ΔG=−£4bn, ΔX=−£1bn\Delta X = -\pounds 1\text{bn}ΔX=−£1bn and ΔS=−£2bn\Delta S = -\pounds 2\text{bn}ΔS=−£2bn, ΔT=+£3bn\Delta T = +\pounds 3\text{bn}ΔT=+£3bn, ΔM=+£2bn\Delta M = +\pounds 2\text{bn}ΔM=+£2bn
ΔI=−£2bn\Delta I = -\pounds 2\text{bn}ΔI=−£2bn, ΔG=+£6bn\Delta G = +\pounds 6\text{bn}ΔG=+£6bn, ΔX=+£3bn\Delta X = +\pounds 3\text{bn}ΔX=+£3bn and ΔS=+£1bn\Delta S = +\pounds 1\text{bn}ΔS=+£1bn, ΔT=+£2bn\Delta T = +\pounds 2\text{bn}ΔT=+£2bn, ΔM=+£2bn\Delta M = +\pounds 2\text{bn}ΔM=+£2bn
