Volume 7, Issue 2, April 2006

The Research Agenda: Pierre-Olivier Gourinchas on Global Imbalances and Financial Factors

The research agenda I will discuss here today focuses on the historical role of financial variables in this adjustment process. My first line of research --with Hélène Rey from Princeton-- shifts the focus of the analysis from the current account to the net and gross international investment positions and the role of valuation effects. My second line of research --with Ricardo Caballero and Emmanual Farhi from MIT-- discusses the role of financial development and emphasizes the global supply of financial assets.

In the following discussion, I consider each in turn.

1. The importance of expected valuation effects

Here is a way to think about the orders of magnitude involved: at the end of 2004, the Bureau of Economic analysis reports US gross external assets and liabilities equal respectively to 85% and 107% of US GDP, implying a NIIP of -22% of GDP. That year, the trade deficit on goods and services reached 5.3% of GDP. The standard approach suggests that the US will need to run significant trade surpluses, at some point in the future, to stabilize its external debt. Part of the adjustment, however, may also come from lower returns on US assets held by foreigners, relative to the return on foreign assets held by the US, i.e. a wealth transfer to the US. Since most US liabilities are denominated in US dollars, and approximately 70% of US foreign assets are denominated in foreign currencies, this wealth transfer can take the form of a depreciation of the US dollar. For instance, consider an unexpected 10% depreciation of the US currency. It implies, ceteris paribus, a transfer of 5.9% (0.7*0.85*0.1) of GDP from the rest of the world to the US that would more than cover the trade deficit. Could it be, then, that movements in currency and asset prices contribute systematically to the adjustment process and if so, by how much?

One may be tempted to dismiss even the possibility of such predictable valuation effects. After all, usual interest parity considerations would rule them out: asset and currency prices should be expected to move in such direction as to deliver similar returns, when measured in a common currency. I will return to this important theoretical issue shortly, but I want to concentrate first on what the data have to say.

The first task is to construct accurate measures of a country's NIIP at market value. In Gourinchas and Rey (2006a), we assemble a quarterly dataset of the US gross foreign asset and liability positions at market value since 1952 disaggregated into four broad asset categories (direct investment, equity, debt and other --mostly bank loans and trade credit), and compute capital gains and total returns on these global portfolios components. This exercise delivers a number of important "stylized facts." First, it is well known that the investment income balance --the balance of interest, dividends and earnings on direct investment paid to and by the US-- has remained positive despite mounting net liabilities. What is less well-known is that the evidence on total return on US external assets and liabilities is consistent with the evidence on yields: since 1952, the US enjoyed an average annual excess return on its gross assets of 2.11%. Moreover, this excess return has increased to 3.32% since the collapse of the Bretton Woods system of fixed exchange rates. About one third of this excess return reflects the role of the US as a world financial intermediary, borrowing mostly in the form of low yield-low risk assets (loans and debt), and investing in high yield-high risks assets (equity and FDI). The remaining two thirds arise from return differentials within asset classes. This reflects mostly the ability of the US to borrow at very low interest rates, a fact sometimes interpreted as evidence of the "exorbitant priviledge" that the US enjoys from its unique position in the international monetary order, as the issuer of the world's reserve currency.

Gourinchas and Rey (2005) turn to the question of the international adjustment process. We cast the analysis in very general terms, relying simply on a country's intertemporal external constraint and a no-Ponzi condition, and characterize two adjustment channels. The traditional "trade channel" links current imbalances to future trade surpluses. The novel "valuation channel" shows that expected future excess returns on the NIIP can also potentially contribute to the process of adjustment. Formally, our empirical approach builds on Campbell and Shiller (1988), who look at the adjustment process of the dividend price ratio, or more recently Lettau and Ludvigson (2001), who look at movements in the consumption-wealth ratio. Like these papers, we construct a measure of cyclical external imbalances --akin to the deviation from trend of the ratio of the trade deficit (the flow) to the NIIP (the stock)-- and relate it to future expected net exports growth and excess returns. In contrast with these papers, we allow for slow moving structural changes in the data, capturing increasing trade and financial integration. The empirical results indicates that up to 27% of cyclical external imbalances are eliminated via predictable adjustments in future returns, and 64% are eliminated via future improvements in the trade balance, accounting for 91% of the fluctuations in external imbalances. We then turn the argument on its head: if the valuation channel is operative, current cyclical imbalances, properly measured, should predict future excess returns, and possibly future currency movements. There again, we obtain very strong predictability results, from 1 to 16 quarters ahead, both in and out of sample. A global imbalance today strongly predicts future positive excess return on US external assets and a future depreciation of the U.S. dollar. This last result is especially striking: the classic paper of Meese and Rogoff (1983), established that no exchange rate model could significantly outperform the random walk at short to medium horizons. Our results decisively overturn their conclusion.

2. Valuation effects: some elements of theory

A successful theory will need two critical ingredients: consumption and portfolio home biases. The former implies that a stabilization of the current account must be accompanied by relative price and real exchange rate movements. The latter requires that domestic and foreign assets are imperfect substitute and implies that wealth transfers are accompanied by predictable and partially offsetting exchange rate movements (see Obstfeld (2004)). The connection between consumption and portfolio home biases is an active topic of research (see Obstfeld and Rogoff (2000), Coeurdacier (2005) and Heathcote and Perri (2005)). Under some conditions, home portfolio bias can emerge as a consequence of the tilt in preferences toward the home good.

Gourinchas and Rey (2006b) build on this literature. We consider a two-country Lucas tree economy with complete markets and preferences for the home good (see Kollmann (2006) for a related model). Preliminary results indicate that, in models with perfect risk sharing, external adjustment operates via strong and unexpected valuation effects, but no predictable valuation effects. The intuition for that result is the following: in an endowment economy, efficient risk sharing requires that a country runs a trade deficit when domestic output is relatively low. To do this, the planner's allocation generates an unexpected valuation gain that offsets current and expected future trade deficits. One way to implement this allocation is for foreigners to hold claims to the domestic tree and vice versa: under reasonable preference assumptions, the negative domestic shock lowers the value of domestic equity relative to foreign equity and generates an unexpected capital loss for foreigners, which turns the domestic country into a net creditor. In the meantime, the decline in the relative supply of the home good requires an instant real appreciation, followed by a subsequent depreciation. Crucially, this expected real depreciation is offset by expected adjustments in asset returns. Therefore it does not generate predictable excess returns nor contributes to the adjustment process.

Looking ahead, the next obvious step is to build general equilibrium models of international portfolio allocation with incomplete markets. I see this as a major task that will close a much needed gap in the literature between effectively complete markets models and the special cases that assume away predictable return or eliminate current account fluctuations (see, inter alia, Baxter and Crucini (1995), Corsetti and Pesenti (2001), Heathcote and Perri (2005), Pavlova and Rigobon (2003), Tille (2005)). One interesting step in that direction is Evans and Hnatkovska (2005).

Along the way, we are witnessing a renewal of interest in the old partial-equilibrium portfolio balance literature of Kouri (1982), and more recently Blanchard Giavazzi and Sa (2005), that generate predictable valuation effects. In these models interest rates are constant and the exchange rate performs the dual role of allocating global portfolios between imperfectly substitutable domestic and foreign assets, and affecting the trade balance through traditional expenditure switching effects. Whether the insights from that literature survive in a modern dynamic global portfolio model is a question of great interest.

3. The global supply of financial assets

Caballero, Farhi and Gourinchas (2006) develop a stylized model to account for these three observations. Its key feature is a focus on the ability of different regions to supply tradable financial assets, and how this impacts equilibrium world interest rates and global capital flows.

The model is quite standard, except for two features. First, it assumes that only a fraction of current and future domestic output can be capitalized into tradable financial claims. The present value of the remaining share of output constitutes a non-tradable financial asset. Second, the model is non-ricardian: as in Blanchard (1985) or Weil (1987), current households do not have full rights over the non-tradable asset: some of these rights might belong to future unborn generations. In a ricardian setting, the relative supply of tradable and non-tradable financial assets is irrelevant: an increase in the share of income capitalized into tradable assets increases the supply of those assets but decreases the supply of non-tradable financial assets by the same amount, and hence raises the demand for tradable financial assets one for one. This leaves equilibrium allocations and interest rates unchanged. By contrast, in a non-ricardian setting, an increase in the share of income capitalized into tradable assets increases the total supply of financial assets and affects equilibrium allocations.

The fraction of output that can be attached to tradable financial assets might differ across countries, reflecting different levels of financial development, of protection of property rights, of intermediation capital or of any financial friction.

The model considers what happens when regions that are good asset suppliers experience a sustained growth slowdown (continental Western Europe and Japan in the early 1990s), or when the quality, or acceptance of financial assets deteriorates (emerging Asia and Russia after the Asian crisis). In both cases, the global supply of financial assets declines. This depresses global interest rates, generates persistent capital flows into the US and an offsetting current account deficit. From the good's market perspective, global declines in the supply of financial assets abroad increases the value of US financial assets, hence US wealth when portfolio are not perfectly diversified. This increases consumption and leads to a trade deficit.

We extend the basic structure along two dimensions. First we allow for domestic and foreign direct investment. Direct investment generates intermediation rents for the US (as documented in Gourinchas and Rey (2006a)) that further relax the US external constraint and finances permanent trade deficits. Second, we introduce heterogeneous goods to discuss real exchange rate determination. The exchange rate patterns generated by the expanded model are consistent with the data, while leaving the broader pattern of capital flows and global returns largely unchanged. In the short run, under the assumption of home consumption bias, the increase in US wealth translates into higher relative demand for US goods and a real exchange rate appreciation. In the long run, we find that the real exchange rate depreciates only moderately.

This line of research highlights the role of financial factors for current imbalances. It indicates that the current configuration of asymmetries is likely to continue until the conditions for the initial imbalances are reversed (higher growth among asset suppliers, Europe and Japan, or financial development among asset demanders, emerging Asia). Along that path, the US may build large net external liabilities. Of course, such leverage is risky. Our framework emphasizes that these risks do not arise unavoidably from the current situation.

References:

EconomicDynamics Interviews David Levine on Experimental Economics

EconomicDynamics: In your 1998 Review of Economic Dynamics article, the most cited so far in this journal, you show that one can easily account for the altruistic and spiteful behavior in dynamic experimental games. How did this article influence subsequent experiments and the relevant literature?

David Levine: There were several elements of that paper: as you indicate, it examines altruism and spite in experimental games. One finding is that altruism and spite cannot be explained as a static phenomenon, but rather arises dynamically as actions by players trigger feelings of altruism and spite by their opponents. However, it is apparent to anyone with a modicum of sense that players in these experiments have altruism and spite, and many papers making this point and proposing various models appeared before I wrote on the subject - Rabin in particular was a leader. There were two innovative elements of the paper. First, it proposed a particular signalling model of altruism and spite. While this approach has not overrun the profession, there is some very beautiful recent work by Gul and Pesendorfer taking an axiomatic approach to interpersonal preferences, of which I am pleased that my rather ad hoc model turns out to be a special case of. However, I think the main element of the paper that was significant was the effort to do quantitative theory - that is, to follow the calibration methodology of looking for a small number of behavioral parameters - in this case measuring attitudes towards other players - that are the same across many different data sets. This methodology has been used with great success by Fehr and Schmidt - who have their own model of altruism and spite ("inequality aversion"), and who have done a great many clever experiments giving players opportunities to punish and reward each other.

ED: In which areas do you see this kind of economic behavior to have an impact? In other words, for which questions may the responses be significantly influenced by this behavior?

DL: It is easier to answer the opposite question: where does altruism and spite not have important economic consequences? I think there is fairly widespread agreement about this: in competitive environments, interpersonal preferences do not play much role, because there is little scope for harming or helping other people. Setting too high a price for your good doesn't harm your customer because they can easily find another seller to sell to them at the competitive price. Similarly, you don't help or harm your competitors who are able to sell pretty much what they want at the competitive price no matter what you do. Setting too low a price helps your customer of course - but you are just transferring value to them on a 1-1 basis, and while the evidence is that people are willing to be altruistic when the gains to the other party are greater than the cost to themselves, they are less willing to do so when the gains and the costs are equal. There is plenty of experimental evidence that in competitive environments the competitive model - with selfish preferences - does quite well; this is the thrust of the first experimental economics literature by Plott, Smith and many others. This idea is also reflected in an earlier literature - particularly by Gary Becker - pointing out that racial discrimination and other related interpersonal preferences do not thrive in a competitive environment.

It should also be emphasized that while some strangers in the lab playing anonymously do behave altruistically and spitefully, the majority behave selfishly. In non-competitive environments, some games are relatively robust to the introduction of some players with deviant preferences; others are not. Centipede grab-a-dollar type games, of the type studied by McKelvey and Palfrey, are very sensitive to players willingness to give money away in the final period. Even more economically important are finitely repeated games. Here a little bit of non-selfish play - willingness to reward an opponent in the last round - goes a long way. It is pretty well established both in the laboratory and out that a long finite horizon can induce quite a bit of cooperation. I think it is pretty likely a consequence of preferences on the part of some people that care mildly about other players. In practice I think a lot of institutions rely pretty heavily on a mild degree of altruism by most people, and a lot of spite by a few. The judicial system - the rule of law - depends in my view quite heavily on this. Without the desire for revenge, many fewer crimes would be reported. Bear in mind that there is an important public goods aspect to reporting crimes. If relatively neutral witnesses didn't have a mild preference for telling the truth and "seeing justice done" it is hard to see how the system could function particularly well.

ED: In game theory, the frequent multiplicity of Nash equilibria is dealt with by refinements that sometimes are quite ad hoc. In which sense are refinements in preferences such as the ones discussed above not subject to this criticism?

DL: I'm not entirely sure of the analogy - the problem of multiplicity is that the theory is inadequate; it does not have enough predictive power. The problem with preferences is that the theory - at least using selfish preferences - is wrong. But the issue of being ad hoc is certainly relevant in both cases.

A great deal of work on preferences that are altruistic and spiteful is ad hoc; and some of it does not stand up well to scrutiny as a result. The big problem I see is that preferences that are an ad hoc solution to one problem at the same time lead to nonsense results, or contradict existing theory in setting where existing theory does quite well. It isn't enough to show that a particular model of altruism and spite solves some particular problem. It has to be shown also that (1) it remains consistent with existing theory in domains where existing theory already works and (2) that is works across a broad variety of different problems where altruism and spite exist.

Moreover, most preference puzzles are quantitative not qualitative, so I think the scope for theories showing that particular modifications to preferences shifts things in the right direction to explain one particular anomaly are not all that useful at this stage. My paper used an ad hoc description of preferences, but tried to bring some of this discipline to bear. Fehr and Schmidt's work has also been aimed at providing broad quantitative solutions.

I also think that axiomatic theory of the type being conducted by Gul and Pesendorfer is an important antidote to the ad hoc approach - it is a good thing, in my view, that the type of preferences I examined satisfy the Gul-Pesendorfer axiom system. The reason that the axiomatic approach is so important is that it gives us a much broader understanding of what preferences are like, what domains they are consistent with selfish preferences over, and some general reassurance that they do not have strange and undesirable features. It is not easy, given a particular functional form, to see transparently what implications that function has in all settings - that is, what axioms it might satisfy and violate. The axiomatic approach also enables us to know which variations on preferences are "reasonable" in the sense of satisfying the same set of axioms, while limiting the range of solutions we look for. How difficult would economics be, for example, if for the most part we did not think that preferences were concave?

References

Review: Singelton's Empirical Dynamic Asset Pricing

This book is at the intersection of modern time series and modern asset pricing theory, two fields that are by themselves already challenging for all graduate students. For those how have mastered the basics, Ken Singleton gives us the ultimate treatise of empirical asset pricing.

The book is structured such that it can be read in different ways: there are purely econometric chapters, only a few of which are required reading for the rest, followed by chapters that cover dynamic asset pricing theory, focussing on pricing kernels, linear and consumption-based models, each first covering theory, then empirical methods that can test them. The last part of the book treats no-arbitrage models in the same way. The author does not just present models and methods, but also likes to discuss results, both from his own, well-known research (with updates) and from the current frontier. Thus it is possible to teach with this book either empirical methods, asset pricing theory itself, or a combination of both.

This book is not an easy read, and thus clearly destined to teach the advanced PhD student or serve as a reference to the researcher. But it is sure to become a classic work in this field. It has all the necessary ingredients: a systematic and thorough coverage of the relevant topics, both the seminal and the latest, and an author who is a pioneer of the field.

"Empirical Dynamic Asset Pricing" is published by Princeton University Press

Review: Bertola, Foellmi and Zweimüller's Income Distribution in Macroeconomic Models

There is a renewed interest in distributional issues in macroeconomics in responses to challenges in the social security system in many countries and concerns about the link between growth and inequality. This textbook fills a gap especially in the analysis of the growth model. There are various kinds of inequalities and the text tries to address all of them mostly with closed-form solutions: inequality in the remuneration of factors, inequality in the distribution of individual income and wealth, and inequality in the product mix.

This textbook does not attempt to be at the very cutting edge of research. Rather it tries to show how one can extend the representative agent model in interesting ways, i.e. how aggregates may influence distributional indicators or vice-versa. Results are generally of analytic nature and focus on key insights.It starts with the neoclassical growth model, gradually making it more complex by endogenising more variables, adding uncertainty in income or lifetimes, introducing market imperfections, market power and multiple goods. The analysis is complemented by numerous exercices and each chapter is concluded by a literature review of extensions.

While this book is probably not appropriate for a standalone graduate macroeconomics class, it can certainly complement one or serve as the basis for a second course. Researchers should also find the book useful to refresh their intuition or to discover new avenues.

"Income Distribution in Macroeconomic Models" is published by Princeton University Press.

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