Dualism and cross-country growth regressions

This paper develops empirical growth models suitable for dual economies, and studies the relationship between structural change and economic growth. Changes in the structure of employment will raise aggregate productivity when the marginal product of labor varies across sectors. The models in the paper incorporate this effect in a more flexible way than previous work. Estimates of the models imply sizeable marginal product differentials, and indicate that the reallocation of labor makes a significant contribution to the international variation in productivity growth.     

Mehr Transparenz in der Bildungspolitik

In a new report, the Academic Advisory Board at the Federal Ministry for Economic Affairs and Energy points out that not all information sources are used to analyse and improve education policy in Germany. Here it is argued that providing information on school policy measures across federal states can create new knowledge and improve outcomes considerably.     

Risk and Regulation in Derivatives (or Why Derivatives Are a Blessing,Not a Curse)

In this article, first published in 1994, the authors aimed to defuse the widespread hysteria about derivatives fueled by media accounts (like Fortune magazine's cover story in the same year) by offering a systematic analysis of the risks to companies, investors, and the entire financial system associated with the operation of the relatively new derivatives markets. Such analysis ended up providing assurances like the following:

• As long as most companies are using derivatives mainly to limit their financial exposures and not to enlarge them in efforts to pad their operating profits, reported losses on derivatives should not be a matter for concern. “Complaining about losses on a swap used to hedge a firm's exposure,” as the authors note, “is like objecting to the costs of a fire insurance policy if the building doesn't burn down.”
• To the extent that companies are using derivatives to hedge—and what evidence we have suggests that most are—the default risk of derivatives has been greatly exaggerated. An interest rate swap used by a B‐rated company to hedge a large exposure to interest rates will generally have significantly less default risk than a AAA‐rated corporate bond issue.
• Thanks to the corporate use of derivatives, much of the impact of economic shocks such as spikes in interest rates or oil prices is being transferred away from the hedging companies to investors and other companies better able to absorb them. And in this fashion, defaults in the economy as a whole, and hence systemic risk, are effectively being reduced, not increased, through the operation of the derivatives markets.

Moreover, the authors warn in closing that the likely effect of then proposed derivatives regulation would be to restrict access to and increase the costs to companies of using derivatives markets. As one example, the excessive capital requirements associated with derivatives facing bank dealers—based on gross rather than net measures of exposure—and which regulators have since proposed extending to nonbank dealers—were expected to have the unintended effect of encouraging dealers to sell precisely the kinds of riskier, leveraged derivatives that Bankers Trust sold Procter & Gamble, and that functioned as Exhibit A in the Fortune article.     

The Supply of Safe Assets and Fiscal Policy

Beyond fleeting references, there is surprisingly little analysis about the interrelationship between fiscal policy and safe assets. This study analyses this interrelationship and argues that, at a certain point, more public debt will not “buy” more safety: countries face a kind of “safe assets Laffer curve”, with a maximum amount of safe assets at some level of indebtedness. The position and stability of this curve depend on a number of national and international factors, including international risk appetite and the quantitative easing policies implemented by central banks. The study also finds evidence of declining safe assets, as reflected in government debt ratings.     

On optimal portfolio diversification with respect to extreme risks

Extreme losses of portfolios with heavy-tailed components are studied in the framework of multivariate regular variation. Asymptotic distributions of extreme portfolio losses are characterized by a functional γ _ξ =γ _ξ (α,Ψ) of the tail index α, the spectral measure Ψ, and the vector ξ of portfolio weights. Existence, uniqueness, and location of the optimal portfolio are analysed and applied to the minimization of risk measures. It is shown that diversification effects are positive for α>1 and negative for α<1. Strong consistency and asymptotic normality are established for a semiparametric estimator of the mapping ξ ↦ γ _ξ . Strong consistency is also established for the estimated optimal portfolio.     

Specifying Human Capital

A review of the measures of the stock of human capital used in empirical growth research – including adult literacy rates, school enrollment ratios, and average years of schooling of the working‐age population – reveals that human capital is mostly poorly proxied. The simple use of the most common proxy, average years of schooling, misspecifies the relationship between education and the stock of human capital. Based on human capital theory, the specification of human capital is extended to allow for decreasing returns to education and for differences in the quality of a year of education. The different specifications give rise to hugely differing measures of the stock of human capital across countries, and development‐accounting results show that misspecified human capital measures can lead to severe underestimation of the development effect of human capital.     

Reduction of Value-at-Risk bounds via independence and variance information

We derive lower and upper bounds for the Value-at-Risk of a portfolio of losses when the marginal distributions are known and independence among (some) subgroups of the marginal components is assumed. We provide several actuarial examples showing that the newly proposed bounds strongly improve those available in the literature that are based on the sole knowledge of the marginal distributions. When the variance of the joint portfolio loss is small enough, further improvements can be obtained.     

Value‐at‐Risk bounds with two‐sided dependence information

Value‐at‐Risk (VaR) bounds for aggregated risks have been derived in the literature in settings where, besides the marginal distributions of the individual risk factors, one‐sided bounds for the joint distribution or the copula of the risks are available. In applications, it turns out that these improved standard bounds on VaR tend to be too wide to be relevant for practical applications, especially when the number of risk factors is large or when the dependence restriction is not strong enough. In this paper, we develop a method to compute VaR bounds when besides the marginal distributions of the risk factors, two‐sided dependence information in form of an upper and a lower bound on the copula of the risk factors is available. The method is based on a relaxation of the exact dual bounds that we derive by means of the Monge–Kantorovich transportation duality. In several applications, we illustrate that two‐sided dependence information typically leads to strongly improved bounds on the VaR of aggregations.     

Do better schools lead to more growth? Cognitive skills, economic outcomes, and causation

We develop a new metric for the distribution of educational achievement across countries that can further track the cognitive skill distribution within countries and over time. Cross-country growth regressions generate a close relationship between educational achievement and GDP growth that is remarkably stable across extensive sensitivity analyses of specification, time period, and country samples. In a series of now-common microeconometric approaches for addressing causality, we narrow the range of plausible interpretations of this strong cognitive skills-growth relationship. These alternative estimation approaches, including instrumental variables, difference-in-differences among immigrants on the U.S. labor market, and longitudinal analysis of changes in cognitive skills and in growth rates, leave the stylized fact of a strong impact of cognitive skills unchanged. Moreover, the results indicate that school policy can be an important instrument to spur growth. The shares of basic literates and high performers have independent relationships with growth, the latter being larger in poorer countries.