Tariffs versus VAT in the presence of heterogeneous firms and an informal sector

The debate over the use of tariffs or value added taxes in developing countries has focused on the difficulty of collecting VAT from the informal sector. This paper contributes by considering this issue with heterogeneous firms and endogenous entry. This yields two results. First, a cut in the tariff reduces the size of the informal sector. Second, the imposition of VAT need not increase the size of the informal sector. Turning to simulation results, we find that switching from a tariff to a revenue-neutral VAT increases welfare, in part because of the selection effect generated by heterogeneous firms.     

American options and callable bonds under stochastic interest rates and endogenous bankruptcy

A new characterization of the American-style option is proposed under a very general multifactor Markovian and diffusion framework. The efficiency of the proposed pricing solutions is shown to depend only on the use of a viable valuation method for the corresponding European-style option and for the transition density of the model’s state variables. Under a Gauss-Markov stochastic interest rates setup, these new American option pricing solutions are shown to offer a much better accuracy-efficiency trade-off than the approximations already available in the literature. This result is also used to price callable corporate bonds under an endogenous bankruptcy structural approach, by decomposing the option to call or default into a European put on the firm value plus two early exercise premium components.     

Stock Market Mean Reversion and the Optimal Equity Allocation of a Long-Lived Investor

This paper solves numerically the intertemporalconsumption and portfolio choiceproblem of an infinitely-lived investor whofaces a time-varying equity premium.The solutions we obtain are very similarto the approximate analytical solutionsof Campbell and Viceira (1999), except atthe upper extreme of the state spacewhere both the numerical consumption andportfolio rules flatten out.We also consider a constrained version ofthe problem in which the investor facesborrowing and short-sales restrictions.These constraints bind when the equitypremium moves away from its mean in eitherdirection, and are particularly severe forrisk-tolerant investors. The constraints havesubstantial effects on optimalconsumption, but much more modest effects onoptimal portfolio choice in theregion of the state space where they are notbinding.     

The role of sharing in the circulation of knowledge

One of the points stressed in ‘A new paradigm in the organization of knowledge’, Futures, 26, 1994, pages 781–786, was the determinant role of sharing in the emergence and configuration of the paradigm of the immaterial. We resume the elements suggested then and develop their analysis in three stages: first, by characterizing the operational singularity of sharing; second, by considering its cognitive and disciplinary incidence; and finally, by pointing out its theoretical consequences, namely in what concerns the thematic of rationality.     

PROLIFERATION OF ACADEMIC JOURNALS: EFFECTS ON RESEARCH QUANTITY AND QUALITY

There have been significant structural changes in research markets in recent years reflected in the increase in the number of academic journals. This paper uses a differential game model of authors and journal editors to examine the effects of an increase in competition among academic journals. Does an increase in the number of academic journals lead to an increase in scholarly articles published? Will an increase in publishing outlets adversely affect research quality? The results show greater competition does not affect research output and in fact enhances research quality. The number of journals and the relative discount rates of authors and editors are crucial determinants of the effects of competition.     

Drug selection: Mozambique

Whereas a few hundred generic drugs are essential for health care, the international and many national markets are flooded with tens of thousands of brand-name preparations. This numerical difference is because of the many imitative products, drug combinations, brandname duplications, and drugs with low therapeutic value and/or unacceptable adverse effects. Since independence Mozambique has reduced the number of registered products, including those for retail pharmacy sale, from some 26,000 to about 1200. An effective national formulary has been introduced for health service use and now contains only 343 distinct therapeutic substances. The formulary uses only international non-proprietary names, and has been used to rationalize state pharmaceutical procurement with cost savings and to improve drug information and use.     

Technical Efficiency of the Brazilian Municipalities: Correcting Nonparametric Frontier Measurements for Outliers

In this paper we estimate the DEA technical efficiency for 4796 Brazilian municipalities, by applying a recently proposed “Jackstrap” method, which combines Bootstrap and Jackknife resampling techniques, to reduce the effect of outliers and possible errors in the data set. We perform calculations to identify and eliminate high leverage municipalities, using different variants of Data Envelopment Analysis (DEA), as well as Free Disposal Hull (FDH). Corroborating previous results, efficiency results for the Brazilian municipalities show a clear relationship between the size of the municipality and its efficiency scores. Indeed, under both DEA variants, smaller cities tend to be less efficient than larger ones hence indicating that the quality of the frontier adjustment improves significantly as the size of the municipality increases. We present arguments that may explain to some extent these findings, such as economies of scale and the excess spending due to revenue from royalties. However, such effects require further, more careful examination.     

Nonlinear stochastic effects of substitution — an evolutionary approach

Technological innovations have been investigated by means of substitution and diffusion as well as evolution models, each of them dealing with different aspects of the innovation problem. In this paper we follow the well known research traditions on self-organisation models of complex systems. For the first time in the literature we show the existence of a specific niche effect, which may occur in the first stage of establishment of a new technology. Using a stochastic Master equation approach, we obtain analytical expressions for the survival probabilities of a new technology in smaller or larger ensembles. As a main result we demonstrate how a hyperselection situation might be removed in a stochastic picture and thresholds against the prevailing of a new technology in a step-by-step process can be overcome.     

The struggle for space: Past and future of the space race

This article is geared toward shedding some more light on what may be the next space race and its contours.Space flight is undoubtedly a human achievement of the second half of the 20th century, and probably the most audacious one of the past century. The space race started suddenly in the 1950s and has grown explosively during the following two decades, but decreased steadily after the 1970s. After the 1990s, however, we have seen a shy rebirth of space-related activities, when many other actors (states) entered the stage, adding up to the agonizing role of the two-actor piece that we have witnessed during the so-called Cold War.The opening years of the 21st century provided a more complex narrative for space exploration. At the start of the new millennium a new technosphere [1] emerged, dominated by what is used to be called as the Information and Communications Technologies (ICT), with the Internet playing the leading role among the bandwagon of technological novelties that appeared during the twilight of space activities. In despite of the fact that artificial satellites represent the very backbone of the global communications system, space activities seem to play a secondary role amidst the apparently accelerated rate of change concerning the technological systems of the present technosphere. But, as it is demonstrated in this paper, things are changing, and very probably a renewed space race will unfold in the coming decades.A question may be placed: what happened? Why the Earth stood still with regard to the race toward the cosmos? Answer: futurists, even prestigious ones like Herman Kahn and Arthur Clarke, did not consider the existence of socioeconomic long waves (Kondratieff waves, or K-waves for short) with their two decades long economic downturn, which has contributed to the deceleration of space-related activities.Analyzing the worldwide evolving scenario of space-related activities during the last eighty years under the framework of the succeeding K-waves and applying some technological forecasting tools, namely the logistic analysis, technological surveillance and intensive data mining, scrutinizing more than 7500 events occurred in the period 1930–2010 related with space activities, it is demonstrated that the space race like the one that we have witnessed until now is a natural growth process that has saturated at the dawn of this century. The same analysis demonstrates that a new growth process in this field might be nowadays under way with contours very different from that imagined by futurists and science fiction writers sixty years ago. Also the main trends in the usage of launching vehicles and satellites are framed and discussed in this paper.     

From unemployed to entrepreneur: The role of the absolute bequest motive

Using the British Household Panel Survey, this paper finds that inheritance has a concave effect on the hours worked by male entrepreneurs. Receiving an inheritance increases the labor supply of unemployed male entrepreneurs; however this effect becomes smaller for higher inheritances.