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.     

Trade unions vs. statistical discrimination: Theory and application to post-apartheid South Africa

A simple model of statistical discrimination is analyzed, which captures some stylized facts of the South African labor market. It shows that this type of discrimination disappears when the wage rates are determined by efficient bargaining between a representative firm and a union, with endogenous membership. This may explain why the wage gap between Black and White workers in post-apartheid South Africa is smaller among unionized workers than among non-unionized ones.     

佩皮尼昂:欧洲城市的未来

佩皮尼昂市以其城市规划，以其过去和未来在社会经济文化方面的巨大发展变化，正无可争辩地列入欧洲都市的网络之中。她的地位也从“大的小城市”变为“小的大城市”。     

The state of theory in three premier advertising journals: a research note

Despite its importance, little is known about the prevalence of theory in the literature on advertising research. Utilising a content analysis of the three premier advertising journals over an 11-year period, it is found that only 17% of articles have made explicit use of theory. Psychology is the discipline from which the greatest number of articles drew their theoretical frameworks, followed by sociology and economics – indeed, theories from marketing and advertising are in the minority. Limitations are noted and implications of the results are discussed.     

On the Use of Price Ratio in Aggregate Supply Response: Some Evidence from the Poultry Industry

The specification of supply/demand relationships has received considerable attention in agricultural economics (Heien 1977). Economic theory has helped provide a basis for the specification of such relationships, one of its contributions being the proposition that prices should be interpreted only in relative terms. This has had a profound influence on model building in agricultural economics, leading a number of researchers to avoid the use of absolute prices in economic analysis. For this reason, numerous market models of the agricultural economy use price ratios as explanatory variables (e.g., Chen; Chen et al.; Heien, 1976; Gerra; Kulshreshtha and Wilson; Rahn; Talpaz; Morzuck et al.; Houck and Gallagher; Wilson et al.); these examples suggest that the use of such ratios is fairly widespread in econometric modeling of the crop and livestock sectors. One of the best examples of price ratios is the "feed cost to price" ratio commonly used in the analysis of livestock supply response. Indeed, since feed cost constitutes a major part of the total production cost in livestock activities, the "feed cost to price" ratio is often considered a proxy for profitability. For this reason, data on such ratios are regularly published for various livestock activities (e.g., USD A). Also, "feed cost to price" ratios are often employed in the specification of models of livestock supply response, (e.g., Chen; Chen et al.; Heien 1976; Gerra; Kulshreshtha and Wilson; Rahn; Talpaz). However, not all models of aggregate supply response follow this approach. For example, Freebairn and Rausser, and Arzac and Wilkinson, use prices as separate variables rather than in ratio forms in their models. In particular, they do not employ price ratios in their livestock and crop supply equations. The existence of these different approaches raises questions about the appropriateness of the use of price ratios in the modeling of aggregate supply.     

Optimal dividend policy and growth option

We analyse the interaction between the dividend policy and the decision on investment in a growth opportunity of a liquidity constrained firm. This leads us to study a mixed singular control/optimal stopping problem for a diffusion that we solve quasi-explicitly by establishing a connection with an optimal stopping problem. We characterize situations where it is optimal to postpone the distribution of dividends in order to invest at a subsequent date in the growth opportunity. We show that uncertainty and liquidity shocks have an ambiguous effect on the investment decision.      

Higher education and firms: on the interaction between research and regional policies

In the European Union, a series of competencies are shared between a central agency called the European Commission, and the governments of the Member States. This paper focuses on two of those policies: research and regional development. Here, we model and discuss how the level of commitment of a central authority toward poor regions affects the design of the best decision-making process. We explore cases of full centralization and full decentralization, and situations where the two levels of government are allowed to take decisions, either simultaneously or sequentially. In the latter case, we make a distinction between a situation where the central agency decides first as in most federations, and one in which it decides second, then being an agent of national governments. This setting is especially relevant for the European Union. We show, in particular, that when the degree of commitment of the center is high, assignment of redistributive competencies to both levels of power is a proxy for centralization. Additionally, the poorer region may find its best interest in an institutional design where the regions decide first.     

FINANCIAL OPERATIONS AND MONETARY STATISTICS: IMPROVED CONCORDANCE IN THE FRENCH NATIONAL ACCOUNTS

National accounts are a powerful means of coordinating different statistical systems. The better their classifications are adapted to the basic statistics or the information blocks one wishes to use, the better the national accounts play their part. This statement explains why, taking the opportunity of revising the whole system, French national accountants tried to improve the concordance between financial operation tables and monetary statistics. Other reasons leading to this attempt can be found in the dissatisfaction of users having to face different and inconsistent financial information such as the monetary statistics on one hand and the financial aggregates of the national accounts on the other; and even more reasons appear in the organizational field since those two statistical systems are issued by two neighbour services of the Banque de France, often depending on the same sources. Further, many propitious factors are converging at the same time: the French financial system is undergoing profound transformations originating as much in the behaviour of economic agents as in the law, and the statistical operations have to adapt to these changes. The national accounts will in the near future include balance sheets in which financial asset holdings are directly comparable to the money supply aggregates. In its first part our paper sets forth the detailed reasons for our attempts, the conditions in which it took place and the present results. We have reached a much better degree of consistency between the two systems, even if the final scheme has not yet been adopted in either the monetary field or in the field of national accounts. But an important question remains open about the durability of the harmonization: we think that it could be relatively uncertain because of the differences in the goals pursued by the two systems and the constraints which they face. That is why in the second part of the paper we tried to review the way such a pragmatic undertaking as ours could call into question the way in which financial operations are described in the system of national accounts. If one agrees with the present boundary between the real and the financial sphere, the articulation must remain somewhat elementary. But if one wants to revise the usual so-called dichotomy between financial and non financial phenomena, we think that a complete rebuilding of the conceptual framework of the accounts has to be done; this would necessitate a considerable amount of theoretical and practical work.     

Measuring scale effects in the allocative profit efficiency

This paper provides an approach to the measurement of the “scale effects” in the allocative profit efficiency. To be specific, we evaluate the improvements of profit that can be accomplished by means of a change in the scale size, once technical efficiency is achieved. New decompositions of the allocative efficiency into a scale effect component and the corresponding residual mix effect component are derived.