Estimation methods for stochastic volatility models: a survey

Abstract.  Although stochastic volatility (SV) models have an intuitive appeal, their empirical application has been limited mainly due to difficulties involved in their estimation. The main problem is that the likelihood function is hard to evaluate. However, recently, several new estimation methods have been introduced and the literature on SV models has grown substantially. In this article, we review this literature. We describe the main estimators of the parameters and the underlying volatilities focusing on their advantages and limitations both from the theoretical and empirical point of view. We complete the survey with an application of the most important procedures to the S&P 500 stock price index.     

Unit and Fractional Roots at the Long Run and the Seasonal Frequencies in Macroeconomic Time Series

In this article, we show that macroeconomic time series may contain unit and fractional roots at both, at zero and at zero and at the seasonal frequencies. The importance of the root at the long run or zero frequency requires in many cases to consider this root at both, separately in an independent polynomial, and also included in the seasonal one. Several Monte Carlo experiments are conducted to examine cases when the root at the zero frequency is not appropriately considered. An empirical application based on the tests of Robinson, Peter M. “Efficient Tests of Nonstationary Hypotheses,” Journal of the American Statistical Association, 89, 1994, pp. 1420–37 is also carried out at the end of the article.The author gratefully acknowledges financial support from the Government of Navarra (“Ayudas de Formación e Investigación y Desarrollo”).     

Testing for Seasonal Fractional Roots in German Real Output

Abstract. This paper examines the seasonal structure of German real GNP per capita by using a version of Robinson's (1994) tests which is suitable in the context of seasonality. This method has several advantages over alternative approaches when testing for seasonal unit roots. First, unlike standard tests, which are nested in AR alternatives, it is embedded in fractional alternatives. Second, it allows testing at the zero frequency and at each of the seasonal frequencies separately. Third, it makes it possible to test for different orders of integration at each of the frequencies simultaneously. The empirical analysis suggests that the real output series may have a unit root at the zero frequency, and fractional rather than unit roots at the seasonal ones. This is in contrast to the findings reported by Lutkepohl et al. (1999) in their study on German money demand, and shows the importance of modelling the seasonal features of the data in alternative ways.     

On the generic impossibility of truthful behavior: A simple approach

Summary We provide an elementary proof showing how in economies with an arbitrary number of agents an arbitrary number of public goods and utility functions quasi-linear in money, any efficient and individually rational mechanism is not strategy-proof for any economy satisfying a mild regularity requirement.The authors wish to thank William Thomson, Salvadpr Barberá, José Angel Silva and an anonymous referee for helpful comments. The remaining errors are our exclusive responsibility. Financial support from DGICYT under project PB 91-0756 and the Instituto Valenciano de Investigaciones Económicas is gratefully acknowledged.     

Capacity precommitment and price competition yield the Cournot outcome

We introduce a simple model of oligopolistic competition where firms first build capacity, and then, after observing the capacity decisions, choose a reservation price at which they are willing to supply their capacities. This model describes many markets more realistically than the model of Kreps and Scheinkman [Kreps, D., Scheinkman, J., 1983. Quantity precommitment and Bertrand competition yield Cournot outcomes. Bell J. Econ. 14, 326–337]. We show that in this new model every pure strategy equilibrium yields the Cournot outcome, and that the Cournot outcome can be sustained by a pure strategy subgame perfect equilibrium.     

Fiscal deficits and inflation

Macroeconomic theory postulates that persistent fiscal deficits are inflationary. Yet empirical research has had limited success in uncovering this relationship. This paper reexamines the issue in light of broader data and a new modeling approach that incorporates two key features of the theory. Unlike previous studies, we model inflation as non-linearly related to fiscal deficits through the inflation tax base and estimate this relationship as intrinsically dynamic, using panel techniques that explicitly distinguish between short- and long-run effects of fiscal deficits. Results spanning 107 countries over 1960-2001 show a strong positive association between deficits and inflation among high-inflation and developing country groups, but not among low-inflation advanced economies.     

Optimal job design in the presence of implicit contracts

We characterize the optimal job design in a multitasking environment when the firms use implicit contracts (i.e., bonus payments). Two natural forms of job design are compared: (i) individual assignment, where each agent is assigned to a particular job and (ii) team assignment, where a group of agents share responsibility for a job and are jointly accountable for its outcome. Team assignment mitigates the multitasking problem but may weaken the implicit contracts. The optimal job design follows a cutoff rule where only the firms with high reputation concerns opt for team assignment. However, the cutoff rule need not hold if the firm can combine implicit incentives with explicit pay‐per‐performance contracts.     

The future of Russian gas exports to East Asia: Feasibility and market implications

For a long time, the Russian government has aimed to diversify gas exports to East Asian countries. This gearing of Russia towards Asia will have great consequences on world energy, the global economy, and geopolitics in the coming years. This paper analyzes the growth potential of Russia's diversification strategy and the impact this policy would have on sales to Europe. As the most likely scenario is for total gas exports to grow at a moderate rate from 2010 to 2030, any increase in sales to Asia could make difficult the raising of exports to Europe. Our thesis is that this trade-off will depend primarily on domestic consumption trends, geographic targeting of investments, and commercial and financial alliances with foreign partners. However, imports from Central Asia, declining exports to Ukraine and Belarus, and Gazprom investments in other gas-producing countries could also affect gas exports and gas distribution among different markets.