第13章至第16章在封闭经济——既不进行国际贸易也不进行国际借贷的经济——框架下发展了宏观经济理论。本章将经济打开。商品、服务和资本现在跨越国境流动，汇率成为核心宏观经济变量。风险极高：汇率危机曾在数月内摧毁数十年的增长成果，而国际货币合作的架构塑造了地球上每个国家的政策空间。
我们从核算框架（国际收支）开始，转向汇率决定（PPP、UIP、多恩布什超调），构建主力双国模型（奥布斯特菲尔德-罗格夫 Redux模型），然后处理重大政策问题：各国何时应该共享货币？如何协调货币政策？主权国家何时会对其债务违约？为什么资本会从穷国"逆流"到富国？
学完本章后，你将能够：
前置知识：第8章（Mundell-Fleming基础）、第13章（动态优化）、第14章（DSGE方法）、第15章（Calvo定价、NK模型）、第16章（Barro-Gordon、FTPL、跨期政府预算约束）。
相关文献：Mundell（1961, 1963）；Fleming（1962）；Dornbusch（1976）；Obstfeld & Rogoff（1995, 1996）；Eaton & Gersovitz（1981）；Lucas（1990）；Calvo（1998）；Balassa（1964）；Samuelson（1964）；Frankel & Rose（1998）；Reinhart & Rogoff（2009）。
每一笔国际交易都记录在国际收支（BOP）中——一个追踪一国与世界其他国家经济往来的复式记账账本。在构建模型之前，我们必须掌握这一核算框架，因为它对任何开放经济的行为施加了铁律般的约束。
经常账户。贸易差额（商品和服务出口减进口）、净初次收入（国外资产收益减对外负债支出）和净二次收入（转移支付）之和。简洁表达式：
其中$X_t$是出口，$M_t$是进口，$r$是净国外资产的收益率，$NFA_{t-1}$是上期末的净国外资产头寸，$NTR_t$是净二次收入（转移支付）。贸易差额$X_t - M_t$反映当期流量；净要素收入项$r \cdot NFA_{t-1}$反映累积国际资产和负债存量的收入；$NTR_t$反映汇款、援助和其他单边转移。
国际收支恒等式。基本核算恒等式：
其中$KA_t$是资本（金融）账户余额，符号约定为资本流入为正。这不是一个行为方程——它是一个核算恒等式，按构造始终成立。经常账户赤字必须由资本账户盈余来融资。
构建一个国家的BOP并验证恒等式$CA + KA = 0$。
考虑一个小型开放经济体，具有以下年度数据（十亿美元）：商品出口：250；商品进口：310；服务出口：80；服务进口：60；净初次收入：-15；净二次收入：-5；FDI流入：30；证券投资流入：45；其他投资流入：25；官方储备变动：-40（储备积累）。
步骤1：商品贸易差额：\$150 - 310 = -60$。
步骤2：服务贸易差额：\$10 - 60 = +20$。
步骤3：经常账户：$CA = (-60) + 20 + (-15) + (-5) = -60$。
步骤4：资本（金融）账户：$KA = 30 + 45 + 25 + (-40) = +60$。
步骤5：验证：$CA + KA = -60 + 60 = 0$。✔ 恒等式成立。
解读：该国经常账户赤字为\$600亿——其消费和投资超过了生产。赤字由\$600亿的净资本流入（FDI、证券投资、银行贷款）融资，部分被\$400亿的储备积累所抵消。
汇率——一种货币以另一种货币表示的价格——可能是开放经济中最重要的价格。本节从长期基准（PPP）到短期套利（UIP），再到多恩布什超调模型，后者解释了为什么汇率比基本面更加波动。
如果一篮子商品在中国的成本为100元，在美国为15美元，PPP预测$E = 100/15 \approx 6.67$元/美元。
其中$e_t = \ln E_t$是对数名义汇率，$\pi_t, \pi_t^*$分别是国内和国外通胀率。相对PPP的实证表现优于绝对PPP——在5年或更长的时间跨度上，通胀差异与汇率变化之间的相关性很强。
如果国内利率高于外国利率2%，UIP预测国内货币将贬值2%。实证上，UIP在短期严重失效——高利率货币倾向于升值，为套利交易者创造超额收益（"远期溢价之谜"）。
超调的幅度为$\Delta e_{impact} = \Delta m + \frac{\Delta m}{\delta \cdot \lambda}$，其中$\lambda$是货币需求的利率半弹性，$\delta$是价格调整速度。价格调整越慢（$\delta$越小），超调越大。（该公式使用了近似$|\mu| \approx \delta \cdot \lambda$，其中$\mu$是系统$\mu^2 + \delta\mu - \delta/\lambda = 0$的稳定特征值。当$\delta$相对于\$1/\lambda$较小时，该近似有效。）
给定10%的永久性货币供给增加，计算瞬时汇率跳跃、长期汇率，并描绘调整路径。
初始稳态：$e_0 = p_0 = 0$（对数标准化）。货币供给增加$\Delta m = 0.10$（10%）。参数：$\delta = 0.3$，$\lambda = 2$。
步骤1：长期汇率：$e_{LR} = e_0 + \Delta m = 0.10$。价格也上升：$p_{LR} = 0.10$。
步骤2：冲击时汇率：$\Delta e_{impact} = 0.10 + \frac{0.10}{0.3 \times 2} = 0.10 + 0.167 = 0.267$。汇率跳至0.267——贬值26.7%，远超长期的10%。
步骤3：初始跳跃后，汇率从0.267逐渐升值至0.10，而价格从0逐渐上升至0.10。
步骤4：冲击时利率下降。随着时间推移，价格上升减少了实际余额，将利率推回世界水平。
关键启示：汇率超调是因为当价格无法变动时，汇率承担了短期调整的全部负担。
图17.1.多恩布什超调相图。$\dot{p}=0$和$\dot{e}=0$轨迹在稳态处相交。货币供给增加使两条轨迹移动；汇率跳至鞍点路径并逐渐收敛。拖动滑块改变冲击大小。
Peter Schiff told Joe Rogan's audience that Bitcoin has no intrinsic value — it's a speculative mania that will end like every bubble before it. Michael Saylor fired back: "Bitcoin is the apex property of the human race." The clash crystallizes the "what is money?" debate that monetary theory has wrestled with for centuries. After learning Dornbusch overshooting — where exchange rate volatility emerges from sticky prices meeting instant asset-market clearing — you can see why Bitcoin's price swings are not a temporary bug but a structural feature of an asset with fixed supply and speculative demand.
中级多恩布什模型富有洞察力但缺乏微观基础——它是临时性的。奥布斯特菲尔德和罗格夫（1995）构建了Redux模型，一个具有垄断竞争、名义刚性和明确福利分析的双国新凯恩斯框架。
当本国货币贬值时，本国商品相对于外国商品变得更便宜（$\hat{\tau}$上升），需求转向本国商品。替代弹性$\theta$决定了这种转换的强度。
两个对称国家；本国货币扩张。计算贸易条件变化、相对消费转移和福利效应。
对称国家（$\gamma = 0.75$），弹性$\theta = 2$，本国货币扩张$\Delta m_H = 5\%$，外国不变。
步骤1：贸易条件变化：$\hat{\tau} = \frac{0.05}{1 + (0.5)(1)} = 0.033$（本国贸易条件恶化3.3%）。
步骤2：支出转换：$\hat{C}_H - \hat{C}_F = 2 \times 0.033 = 0.067$（相对需求转移6.7%）。
步骤3：本国产出增长约6.7%。本国福利增益约4.2%（产出增益减去贸易条件损失）。
步骤4：外国产出下降约1.7%，但外国享受贸易条件改善。外国净福利是不确定的。
关键启示：Redux模型表明开放经济中的货币政策涉及产出刺激与贸易条件恶化之间的权衡。高度开放（低$\gamma$）使以邻为壑反噬自身效应更可能出现。
图17.2.PPP与实际汇率。45度线以上的国家货币被低估；以下的被高估。巴拉萨-萨缪尔森模式可见：低收入国家系统性地位于线上方。在不同年代之间切换。
图17.3.双国Redux模型。本国和外国货币冲击通过支出转换相互作用。对称冲击相互抵消；非对称冲击产生赢家和输家。本国偏好调节溢出效应的大小。拖动滑块探索。
各国何时应该放弃本国货币而采用共同货币？蒙代尔（1961）的最优货币区（OCA）理论提供了分析框架。
正式的权衡：收益$B = \phi \cdot \tau$（贸易份额乘以交易成本节约）。成本$C = \alpha \cdot \sigma^2_{asymmetric} / \mu$（冲击不对称性除以替代调整机制）。当$B > C$时，货币联盟是最优的。
弗兰克尔和罗斯（1998）认为OCA标准是内生的：加入货币联盟会增加双边贸易并可能使商业周期同步。事前不满足标准的国家可能在事后满足。
评估假想的国家对是否满足蒙代尔标准。
考虑阿尔法国和贝塔国。评分（0-10）：劳动力流动性：3（不同语言、限制性政策）。财政转移：2（无超国家权力机构）。贸易开放度：8（35%的双边贸易）。冲击对称性：5（多元化但结构不同）。金融一体化：7（交叉上市银行、自由资本流动）。评估：高贸易和金融一体化有利于联盟，但低劳动力流动性和缺乏财政转移意味着非对称冲击难以被吸收——类似于欧元区外围国家。
图17.4.OCA标准雷达图。所有轴上的分数越高=建立货币联盟的论据越强。阈值环（分数6）代表最低可行OCA。美国各州占主导地位；欧元区外围在冲击对称性和财政转移方面明显薄弱。选择区域进行比较。
You now have the international dimension. The impossible trinity, OCA theory, and Dornbusch overshooting all constrain what central banks can do once the economy is open. This is the final stop.
Dornbusch overshooting shows that monetary policy affects the exchange rate, which overshoots its long-run level — creating volatility that the central bank did not intend. For small open economies, monetary policy works partly through exchange rate depreciation, which is a beggar-thy-neighbor effect that shifts demand from foreign to domestic goods. The impossible trinity constrains the policy space: a country cannot simultaneously maintain free capital flows, a fixed exchange rate, and independent monetary policy. OCA theory reveals that the Eurozone fails on most Mundell criteria — labor mobility, fiscal transfers, synchronized cycles — meaning the ECB's one-size-fits-all rate is too tight for some members and too loose for others.
The ECB's one-size-fits-all policy was too tight for Greece and too loose for Germany during the sovereign debt crisis. A single central bank for diverse economies cannot control all of them effectively — this is central bank loss of control through institutional design. More broadly, for small open economies with open capital accounts, the exchange rate regime determines the scope of monetary policy. Under a fixed exchange rate with free capital flows, domestic monetary policy is entirely subordinated to the peg — the central bank becomes a currency board, not a macroeconomic manager. Even under floating rates, the "fear of floating" literature (Calvo and Reinhart, 2002) shows that most central banks in practice intervene heavily, constrained by original sin, balance sheet effects, and pass-through to inflation.
The ECB evolved through crisis — OMT ("whatever it takes"), PEPP, and expanded asset purchases broadened its toolkit. The IMF moved toward accepting capital flow management measures as legitimate policy tools. But the fundamental tension remains: one rate for twenty economies cannot be optimal for all of them. The post-2020 debate about global inflation demonstrated that even the Fed operates in an international context — dollar tightening transmitted contractionary impulses to emerging markets through capital outflows and currency depreciation.
Across five stops — IS-LM (Ch 8), expectations and Mundell-Fleming (Ch 9), the NK framework and ZLB (Ch 15), time inconsistency and FTPL (Ch 16), and now the international dimension — the answer has progressively narrowed. Central banks can control the economy, but only under increasingly restrictive conditions: (a) independence from fiscal pressure, (b) not being at the ZLB, (c) understanding the transmission mechanism, (d) the fiscal authority not undermining them, and now (e) the exchange rate regime permitting independent policy. The most honest answer: "usually, approximately, under favorable conditions" — and those conditions are more demanding than the profession acknowledged before 2008. For small open economies, the answer is often "barely." For currency unions, the answer depends on which member you ask.
The rise of digital currencies, CBDCs, and capital flow volatility is creating new challenges for central bank control. If stablecoins denominated in dollars circulate globally, does the Fed become the world's central bank by default? If CBDCs enable instant cross-border payments, does the impossible trinity bind even tighter — or does it loosen? These questions connect to BQ10 (what is money?) and remain at the frontier of international monetary economics.
The Eurozone fails most OCA criteria. The sovereign debt crisis confirmed the costs. But the political project endures — and the counterfactual is unknowable.
高级Bitcoin promised money without the state. CBDCs promise the state's money without banks. Neither has replaced central banking — but both are reshaping the monetary landscape.
高级当一国的货币政策通过汇率溢出到其他国家时，不协调的政策就变成了一个策略博弈。每个国家都有扩张的动机，但当所有国家同时扩张时，汇率效应相互抵消，只剩下通胀。
维持合作需要制度：IMF、G7/G20、广场协议和卢浮宫协议，以及央行互换协议。在重复博弈中，合作可以通过触发策略来维持。
建立一个2×2的货币政策博弈，计算收益，找到Nash均衡，并展示合作改进。
两个对称国家选择扩张（E）或紧缩（T）。收益（损失值，越低越好）：(E,E)=(3,3)，(E,T)=(1,5)，(T,E)=(5,1)，(T,T)=(2,2)。扩张对两者都是优势策略。Nash均衡：(E,E)损失为3。合作结果：(T,T)损失为2。剩余 = 每国1。
关键启示：国际货币政策是一个囚徒困境。每个国家理性地追求竞争性贬值，但集体结果比协调克制更差。
图17.7.政策协调博弈。2×2收益矩阵显示每个国家在扩张与紧缩下的损失。Nash均衡（红色）在Pareto意义上劣于合作结果（绿色）。溢出效应越大，差距越宽。拖动溢出效应滑块。
主权债务与私人债务有根本区别：不存在国际破产法庭。主权偿债本质上是自愿的——一个国家偿还债务是因为违约的成本超过了偿债的成本。
给定初始债务/GDP = 90%，基本盈余 = 1%，增长率 = 2%，利率 = 4%，计算债务轨迹和稳定盈余。
步骤1：利率-增长差异：$r - g = 4\% - 2\% = 2\%$。
步骤2：稳定盈余：$s^* = (r - g) \cdot d_0 = 0.02 \times 0.90 = 1.8\%$占GDP。
步骤3：实际盈余（1%）低于$s^*$（1.8%）。债务将随时间上升。
步骤4：轨迹：第1年：90.8%，第5年：94.2%，第10年：98.8%，第20年：109.4%，第30年：122.5%。
步骤5：要在90%稳定，需要$s^* = 1.8\%$。要在20年内降至60%：约$s = 3.0\%$。
关键启示：如果债权人要求更高的利率（风险溢价反馈），稳定盈余将跳升——形成"债务陷阱"动态。
图17.5.主权债务可持续性。轨迹取决于利率-增长差异（$r - g$）和基本盈余。当$r > g$且盈余不足时，债务爆炸性增长。当$r < g$时，即使存在小额赤字，债务也会稳定。拖动滑块探索。
标准理论预测资本应从富裕国家（资本充裕、边际产出低）流向贫穷国家（资本稀缺、回报率高）。数据讲述了一个不同的故事。
卢卡斯计算，如果$Y = AK^\alpha L^{1-\alpha}$，印度和美国之间的边际产出比率应约为58:1。然而资本并未涌入印度。
2008年后的共识已转向接受资本流动管理措施（CFMs）的某些作用。IMF的制度观点（2012年，2022年修订）承认，当资本流入激增时，CFMs作为临时措施可能是适当的。
图17.6.突然停止模拟器。资本流动逆转迫使即时经常账户调整。汇率制度决定了痛苦落在汇率（浮动）还是产出（固定）上。调整逆转幅度和制度。
凯拉尼面临迄今最严重的危机。在商品冲击（第14章）和零利率下限事件（第15章）之后，外国投资者突然撤出资本。证券投资从占GDP +6%逆转为一个季度内的-4%——典型的突然停止。
BOP危机。凯拉尼占GDP 8%的经常账户赤字突然无法融资。BOP恒等式迫使即时调整：经常账户必须摆动10个百分点。出口无法在一夜之间增加，因此调整落在进口上。
汇率反应。在凯拉尼的有管理浮动汇率制下，货币贬值25%。这触发了支出转换效应，但也恶化了债务：40%的主权债务以美元计价（原罪）。有效债务/GDP从85%跳升至95%。
债务可持续性。$d = 95\%$，$r = 6\%$，$g = 1\%$：$s^* = (0.06 - 0.01) \times 0.95 = 4.75\%$占GDP。当前盈余：仅1%。差距巨大。
解决方案。凯拉尼接受了调整后的IMF方案：适度财政整顿（$s = 3\%$）、债务重新安排（延长期限，非削减面值）和临时资本流动管理。危机趋于稳定但留下了伤疤：产出低于趋势5%，债务需要十年才能恢复到危机前水平。
凯拉尼危机展示了每一个概念：BOP核算、支出转换、原罪、债务可持续性动态、主权违约风险，以及国际政策协调对小型经济体的局限性。
亚洲金融危机（1997-98年）和欧洲主权债务危机（2010-12年）：两场危机跨越了开放经济政策的光谱。
亚洲：泰铢钉住汇率制于1997年7月崩溃。资本流入从占GDP +10%在数月内逆转为-10%。危机暴露了不可能三角：泰国试图同时维持固定汇率、开放资本账户和独立的货币政策。IMF方案开出了紧缩和高利率的药方——对于一场资本账户危机来说争议很大。马来西亚实施了资本管制并以类似速度复苏，挑战了华盛顿共识正统。原罪放大了危机，因为40-80%的货币贬值使以美元计价的企业债务膨胀。
欧洲：希腊、爱尔兰、葡萄牙、西班牙和意大利在货币联盟内面临主权债务危机。没有本国货币，它们无法通过贬值来恢复竞争力——这正是OCA标准失败的体现。希腊的债务可持续性算术令人警醒：$s^* = (0.07 - (-0.04)) \times 1.30 = 14.3\%$占GDP——不可能实现的规模。ECB的"不惜一切代价"（Draghi，2012年）消除了多重均衡问题，但根本的结构性问题——有货币联盟而无财政联盟——仍然存在。
You now see that trade is inseparable from capital flows and exchange rates. A trade deficit is a capital account surplus — the "global imbalances" debate can't be understood through trade alone.
BOP accounting forces a fundamental insight: $CA + KA = 0$. A trade deficit means capital inflow — foreigners are investing in your country. The US trade deficit with China reflects, in part, Chinese savings flowing into US assets. Exchange rate movements can mitigate trade imbalances — a depreciating currency makes exports cheaper through expenditure switching. The impossible trinity constrains policy responses: a country cannot simultaneously fix its exchange rate, allow free capital flows, and run independent trade-balancing monetary policy.
Currency manipulation complicates the free trade story. China's managed exchange rate kept the yuan undervalued for decades, providing an unfair trade advantage — this isn't free trade, it's subsidized trade via exchange rate policy. Dutch disease shows that large capital inflows can appreciate the currency and destroy export competitiveness in non-resource sectors, concentrating the economy in a narrow base. The "global savings glut" thesis (Bernanke, 2005) suggests that persistent US deficits were driven not by US profligacy but by excessive savings abroad — meaning the trade imbalance reflected macro distortions, not comparative advantage at work.
The IMF has moved toward surveillance of "external imbalances" and currency manipulation. The mainstream now recognizes that persistent large imbalances can be destabilizing, even if they're consistent with each country's optimal savings-investment behavior. The 2008 crisis was partly a story of global imbalances: Asian savings flowed into US mortgage-backed securities, fueling a credit boom whose collapse nearly destroyed the global financial system. The trade story and the capital flow story are the same story told from different sides of the BOP identity.
Trade deficits are neither inherently good nor bad — they reflect intertemporal trade (borrowing from abroad to invest at home can be optimal). But persistent, large imbalances can create vulnerabilities: the 2008 crisis, the European sovereign debt crisis, and multiple emerging market sudden stops were all partly stories of unsustainable external positions. The exchange rate dimension means trade policy cannot be analyzed in the partial-equilibrium supply-and-demand framework of Chapter 2. Whether trade is "good" depends not just on comparative advantage but on capital flows, exchange rate regimes, and the institutional capacity to manage the adjustment costs.
The Stolper-Samuelson losers still haven't been compensated. The political backlash against trade — Brexit, Trump tariffs, de-globalization — is a response to real economic losses that the profession understated for decades. Come back at Chapter 20 (§20.8) for the development perspective: East Asia's success involved strategic trade policy, not pure free trade. The question of whether industrial policy can work — and under what institutional conditions — is the next frontier.
The China shock literature quantified persistent, concentrated losses. But the BOP identity says the trade deficit is a capital account surplus — maybe America was importing savings, not exporting jobs.
中级Tariffs raise revenue, protect some industries, and invite retaliation. In a world of global value chains, taxing imports means taxing your own exports.
中级Money's nature is further complicated by the international dimension. Exchange rates are prices of moneys — and the dollar's special status as reserve currency gives the US an "exorbitant privilege." The question becomes: why is the dollar the world's money? This is the final stop.
PPP says that in the long run, exchange rates adjust so identical goods cost the same across currencies. UIP says interest rate differentials reflect expected exchange rate changes. In theory, all moneys are fungible up to an exchange rate. The dollar's reserve currency status means global demand for dollars exceeds what purchasing-power considerations would imply — the US can borrow cheaply, run persistent trade deficits, and extract seigniorage from the global system. The NIIP data tell the story: the US has accumulated over \$18 trillion in net international liabilities, yet continues to earn more on its foreign assets than it pays on its foreign liabilities — the "exorbitant privilege" is real and measurable.
The dollar's reserve status isn't a natural market outcome — it was constructed through Bretton Woods, maintained by military power and network effects, and sustained by the lack of credible alternatives. De-dollarization efforts (BRICS, yuan internationalization, CBDCs) are attempts to rebalance this power. Bitcoin and stablecoins propose an even more radical alternative: money without a state. If money is a convention, a decentralized convention might be more stable than one controlled by self-interested governments. The counterargument is sharp: you can't pay taxes in Bitcoin, and you can't easily price goods in a unit that fluctuates 10% per month. Dollarization and "original sin" show that even sovereign nations cannot always sustain their own currency — they end up pricing debt in dollars because that's where the trust is.
The post-Bretton Woods system (floating rates since 1973) was supposed to be symmetric — each country controls its own money. In practice, it is a dollar system. The GFC and COVID both reinforced dollar dominance through flight-to-safety dynamics. CBDCs represent the next frontier: central bank digital currencies could enable instant cross-border settlement, programmable money, and disintermediation of correspondent banking. China's digital yuan, the ECB's digital euro, and the Fed's cautious exploration all reflect the recognition that the form of money is changing — even if its fundamental nature (a self-reinforcing convention backed by institutional trust) may not be.
Across three stops — IS-LM's treatment of money as a policy quantity (Ch 8), the deep theories of CIA, MIU, and FTPL (Ch 16), and now the international dimension — the answer is that money is deeply political. The dollar's dominance is a geopolitical fact that shapes trade, capital flows, and the global power structure. The theoretical question "what is money?" has a practical answer in international finance: money is whatever the dominant power says it is, sustained by network effects, institutional inertia, and the lack of a credible alternative. The different theories from Chapter 16 each illuminate one face: CIA captures the transaction role, MIU captures the convenience yield, FTPL captures the fiscal backing, and chartalism captures the state's role. No single theory is complete. Money is a self-reinforcing equilibrium of mutual acceptance, maintained by institutions — and when those institutions operate across borders, the equilibrium becomes geopolitical.
Will digital currencies reshape what money is? CBDCs could enable programmable monetary policy, instant cross-border settlement, and the disintermediation of the banking system. Stablecoins could create private money at scale. Bitcoin continues to test whether money needs a state. The technology allows possibilities that existing theory hasn't fully absorbed. Whether this is a monetary revolution or a technological evolution within the existing institutional framework is the defining open question of 21st-century monetary economics.
Peter Schiff says Bitcoin is digital tulips. Michael Saylor calls it the apex property. The Rogan debate crystallizes: which theory of money is right, and what does it predict about Bitcoin?
中级The dollar has been the world's reserve currency since Bretton Woods. De-dollarization is a slow process with no clear destination — and every crisis reinforces the dollar's centrality.
高级Bitcoin promised money without the state. CBDCs promise the state's money without banks. Neither has replaced central banking — but both are reshaping the monetary landscape.
高级| 标签 | 公式 | 描述 |
|---|---|---|
| Eq. 17.1 | $CA_t = X_t - M_t + r \cdot NFA_{t-1} + NTR_t$ | 经常账户 |
| Eq. 17.2 | $CA_t + KA_t = 0$ | BOP恒等式 |
| Eq. 17.3 | $E = P / P^*$ | 绝对PPP |
| Eq. 17.4 | $\Delta e_t = \pi_t - \pi_t^*$ | 相对PPP |
| Eq. 17.5 | $E_t[e_{t+1}] - e_t = i_t - i_t^*$ | 非抛补利率平价 |
| Eq. 17.6 | $q_t = e_t + p_t^* - p_t$ | 实际汇率 |
| Eq. 17.7 | $\dot{e} = \theta(\bar{e} - e)$ | 多恩布什汇率动态 |
| Eq. 17.8 | $\dot{p} = \delta(e - p + p^*)$ | 多恩布什价格调整 |
| Eq. 17.9 | $C = [\gamma^{1/\theta} C_H^{(\theta-1)/\theta} + (1-\gamma)^{1/\theta} C_F^{(\theta-1)/\theta}]^{\theta/(\theta-1)}$ | CES消费聚合函数 |
| Eq. 17.10 | $\hat{C}_H - \hat{C}_F = \theta \cdot \hat{\tau}$ | 支出转换 |
| Eq. 17.11 | $L_i = (\pi_i - \bar{\pi})^2 + \alpha(y_i - \bar{y})^2 + \beta(e_i)^2$ | 政策损失函数 |
| Eq. 17.12 | $L^{Nash} > L^{Coop}$ | 协调收益 |
| Eq. 17.13 | $V^{Repay}(b) \geq V^{Default}$ | 伊顿-格索维茨偿付条件 |
| Eq. 17.14 | $\Delta d_t = (r_t - g_t) d_{t-1} - s_t$ | 债务可持续性动态 |
| Eq. 17.15 | $i_t = i_t^{rf} + \rho(d_t, s_t, g_t)$ | 主权风险溢价 |
| Eq. 17.16 | $f'(k) = r + \delta$ | 新古典资本配置 |
Coming in Part VI: theory meets the real world. Institutions, behavior, and development.