Changes in the AD-AS Model in the Short Run · 短期内 AD–AS 模型的变动
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| demand-pull inflation/dɪˈmænd pʊl ɪnˈfleɪʃn/ | 需求拉动型通货膨胀 | xū qiú lā dòng xíng tōng huò péng zhàng |
| stagflation/stæɡˈfleɪʃn/ | 滞胀 | zhì zhàng |
| stagnant/ˈstæɡnənt/ | 停滞 | tíng zhì |
When a curve moves
- The AD-AS model earns its keep when something shifts a curve.
- Shift AD, and read the new crossing with SRAS.
- Shift SRAS, and read the new crossing with AD.
- The direction the price level and output move tells you which curve shifted.
当一条曲线移动
- AD-AS 模型在某样东西移动一条曲线时才真正发挥作用。
- 移动 AD,读出它与 SRAS 的新交点。
- 移动 SRAS,读出它与 AD 的新交点。
- 价格水平和产出移动的方向,告诉你哪条曲线移动了。
A shift in aggregate demand
- Shift AD right (more confidence, a tax cut, more government spending). Along the upward SRAS, the new crossing is higher.
- The price level rises — this is demand-pull inflation 需求拉动型通货膨胀.
- Real output rises and unemployment falls.
- Signature of an AD shift: price level and output move the same direction.
总需求的移动
- AD 右移(信心更足、减税、政府支出增加)。沿向上的 SRAS,新交点更高。
- 价格水平上升——这就是需求拉动型通货膨胀(demand-pull inflation)。
- 实际产出上升,失业下降。
- AD 移动的标志:价格水平和产出朝同一方向移动。
Shock the economy · 冲击这个经济
An AD shift moves price and output the same way (demand-pull inflation); a supply shock moves them opposite (stagflation). Try each. · AD 移动让价格和产出同向(需求拉动型通胀);供给冲击让它们反向(滞胀)。都试一试。
A rightward shift in AD causes, in the short run: · AD 右移在短期造成:
Along the upward SRAS, more demand raises both price and output — price and output move together. · 沿向上的 SRAS,更多需求同时抬高价格和产出——价格和产出一起动。
Inflation driven by a rightward shift in AD (too much spending) is called ______-pull inflation. · 由 AD 右移(支出过多)驱动的通胀被称为______拉动型通货膨胀。
Demand-pull inflation comes from AD rising faster than supply. · 需求拉动型通胀来自 AD 上升快于供给。
A supply shock
- A negative supply shock shifts SRAS left. Along the downward AD, the new crossing is higher and to the left.
- The price level rises while real output falls — the opposite directions.
- This painful combination is stagflation 滞胀: a stagnant 停滞 economy and rising prices at once.
- It is hard to cure: fighting the inflation deepens the slump, and vice versa.
一次供给冲击
- 负面供给冲击使 SRAS 左移。沿向下的 AD,新交点更高、更靠左。
- 价格水平上升,同时实际产出下降——相反的方向。
- 这种痛苦的组合是滞胀(stagflation):经济停滞(stagnant)且价格上涨同时发生。
- 它难以医治:压通胀会加深衰退,反之亦然。
A negative supply shock (SRAS shifts left) causes: · 负面供给冲击(SRAS 左移)造成:
Along the downward AD, less supply raises the price level while cutting output. · 沿向下的 AD,供给减少抬高价格水平、削减产出。
Stagflation is falling output and rising unemployment together with rising prices. · 滞胀是产出下降、失业上升,同时价格上涨。
That painful mix is exactly what an adverse supply shock produces. · 这种痛苦的组合正是不利供给冲击所产生的。
Why is stagflation hard to cure with demand policy? · 为什么滞胀难以用需求政策医治?
The two problems pull demand policy in opposite directions, so no single AD move solves both. · 两个问题把需求政策拉向相反方向,所以单一的 AD 变动无法同时解决两者。
Two different signatures
- Worked idea. A drought sharply raises food and energy costs — a supply shock. SRAS shifts left, so the price level rises (say index 110 → 115) while output falls (1,000b → 960b): higher prices with lower output is stagflation.
- Contrast a rightward AD shift, which raises price and output together.
- Demand shifts never cause stagflation.
- Read the two directions, and you know which shock hit.
两种不同的标志
- 例题。 一场干旱大幅抬高食品和能源成本——一次供给冲击。SRAS 左移,所以价格水平上升(比如指数 110 → 115),同时产出下降(1,000 十亿 → 960 十亿):价格更高同时产出更低就是滞胀。
- 对比 AD 右移,它让价格和产出一起上升。
- 需求移动从不造成滞胀。
- 读出这两个方向,你就知道是哪种冲击。
Price level and output moving in opposite directions is the signature of: · 价格水平和产出朝相反方向移动,是什么的标志:
Demand shifts move them together; only a supply shock moves them apart. · 需求移动让它们一起动;只有供给冲击让它们分开。
An AD shift moves the price level and output the same direction (a rightward shift gives demand-pull inflation). A supply shock moves them opposite — a leftward SRAS shift gives stagflation (falling output with rising prices), which is hard to cure.
AD 移动让价格水平和产出朝同一方向(右移带来需求拉动型通货膨胀)。供给冲击让它们朝相反方向——SRAS 左移带来滞胀(产出下降同时价格上涨),难以医治。