Optimal time to sell a stock in the Black–Scholes model: comment on ‘Thou shalt buy and hold’, by A. Shiryaev,Z. Xu and X.Y. Zhou

We reconsider the problem of the optimal time to sell a stock studied by Shiryaev et al. (2008 Shiryaev, A, Xu, Z and Zhou, XY. 2008. Thou shalt buy and hold. Quant. Finan., 8: 765–776. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) (following in this issue of Quantitative Finance) using path integral methods. These methods allow us to confirm the results obtained by these authors and extend them to the entire parameter region. We also obtain the full distribution of the time t_m at which the maximum of the price is reached for arbitrary values of the drift.     

A re-examination of the technological catching-up hypothesis across OECD industries

This study re-examines the catching-up hypothesis at the industry level across the main OECD countries, using panel data econometric models involving technological gap indicators calculated with a nonparametric distance function suggested by Färe et al. [Färe, R.S., Grosskopf, M.N., Norris, M., Xhang, Z., 1994. Productivity growth, technical progress, and efficiency change in industrialized countries. American Economic Review 84, 66–83]. The results show that there is statistical evidence of a catching-up process at the industry level. Moreover, both tradables and nontradables sectors exhibit catching-up effects and technology adoption from abroad. This result complements the findings by Bernard and Jones [Bernard, A.B., Jones, C.I., 1996a. Comparing apples to oranges: productivity convergence and measurement across industries and countries. American Economic Review 86(5), 1216–1238., Bernard, A.B., Jones, C.I., 1996b. Productivity across industries and countries: Time series theory and evidence. Review Of Economics and Statistics 78, 135–146], Gouyette and Perelman [Gouyette, C., Perelman, S., 1997. Productivity convergence in OECD services industries. Structural Change and Economic Dynamics 8, 279–295] and Hansson and Henrekson [Hansson, P., Henrekson, M., 1997. Catching up, social capability, government size and economic growth, in V. Bergström, eds, Government and Growth, Oxford: Clarendon Press, 61–126] that there is no (or even a slow) catching-up effect in the manufacturing sector. Moreover, social capability indicators evaluated for each country show that “Non-European” and “Central European” tradables sectors have a rather similar degree of inefficiency while “North European” countries are less efficient for both tradables and non-tradables. Lastly, both the cross country and the cross sectors dispersions of inefficiency levels are smaller for tradables sectors than for non-tradables.     

Mineral wealth and human capital accumulation: a nonparametric approach

This article uses a nonparametric approach to investigate the nexus between mineral wealth and human capital accumulation across countries. Higher mineral wealth is associated with elevated levels of human capital in a cross-section of countries. Matching the overall level of economic development and political instability and violence, weakens but does not reverse this conclusion. These results are economically significant. Moving up from the bottom to the top quartile for subsoil wealth per capita decreases illiteracy by ≈ 12% among young and adult females. Conversely, moving down from the top to the bottom quartile for subsoil wealth per capita decreases the average years of primary and total education by ≈ 1.5 years for females. Results are consistent with Hirschman's conjecture that enclave economies have weaker production linkages but stronger government revenue linkages than other activities. Most importantly, this article argues that caution should be exercised when discouraging countries from exploiting their mineral wealth, especially for countries where human capital is scarce.

I know, [there is] no safe depositary of the ultimate powers of society, but the people themselves; and if we think them not enlightened enough to exercise their control with wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education. This is the true corrective of abuses of constitutional power.     

Time consistent export quotas in an oligopolistic world market

We investigate the strategic behavior between exporting countries that face endogenous terms of trade on the world market. In a non-cooperative setting, if production decisions occur before consumption decisions, the ex-ante optimal export quota is not time consistent as the ex-post elasticity of the residual foreign import demand curve is lower than the ex-ante elasticity. However, we show that the exporters’ inability to irrevocably commit to their quota may be welfare superior to the precommitment solution. If exporters can sell forward a proportion of their exports before production decisions are made, they will do so even though, in equilibrium, it may decrease welfare compared to a situation in which forward markets do not exist. Moreover, the equilibrium with forward markets is welfare inferior to the commitment equilibrium for exporters.     

Physical infrastructure as a constraint on agricultural growth: The case of sub‐Saharan Africa

Abstract

The importance of agriculture in sub‐Saharan Africa, and the somewhat lagging development in other activities, suggests that particular significance attaches to the arrest of the drawn out crisis of agricultural production. Two opposing suggestions which are often made are that this is a matter either of price incentives, or of fundamental change designed to remove many infrastructural constraints and the lack of provision of other essential services. The issues are pursued, first, by an appraisal of the evidence relating to agricultural supply response. The long‐run response to price incentives is probably rather low, but it is suggested that it is very often constrained by non‐price factors. The paper then assesses the importance of infrastructural constraints, particularly in transport and communications. It is argued that the choices between improving price incentives and the need for infrastructure and other provision are not absolute since complementarities are important. Both, in effect, can also compete for public funds. The dilemma is particularly acute in sub‐Saharan Africa since low population densities and long distances result in the costs of transport and other essential services being comparatively high. It is therefore all the more necessary to seek cost‐effective ways of improving provision in order to maximize the impact on farm output. The paper suggests a number of ways in which this can be done, notably by better utilization of existing infrastructure.     

Tariff-Rate Quota Liberalization: The Case of World Price Uncertainty and Supply Management

This paper examines the options for liberalizing tariff-rate quotas when a marketing board controls domestic production and international prices are stochastic. Lowering over-quota tariff and increasing import quota volumes are not equivalent. The trade-offs between the two types of trade reforms are examined through numerical simulations for the Canadian chicken industry. Introducing world price variability results in a distribution of welfare impacts for the different groups in the industry. Consumers and processors gain more with tariff liberalization than with increased import quotas. The difference in producer surplus between liberalization regimes is truncated so that producers only see down-side risk under the tariff liberalization regime.
Le présent article a examiné les options concernant la libéralisation des contingents tarifaires lorsqu'un office de commercialisation encadre la production nationale et que les prix internationaux sont stochastiques. Diminuer le taux de droit hors contingent et augmenter les volumes de contingent d'importation ne sont pas des options équivalentes. Nous avons examiné les deux types de réforme commerciale en effectuant des simulations numériques pour le secteur du poulet au Canada. Incorporer la variabilité du prix mondial provoque une distribution de répercussions sur le bien-être des divers groupes du secteur. Les consommateurs et les transformateurs gagnent davantage en appliquant une libéralisation des droits hors contingent qu'en appliquant une augmentation des contingents d'importation. La différence quant au surplus des producteurs entre les régimes de libéralisation est tronquée de sorte que les producteurs ne voient que le risque de perte sous un régime de libéralisation tarifaire.     

Standardization of Network Technologies: Market Processes or the Result of Inter‐Firm Co‐operation?

As recent studies on the evolution of a technology indicate, the role of a standard, or dominant design, is highly significant in a number of contemporary industries such as computer, telecommunications and consumer electronics. Following Katz' and Shapiro's pioneering works (1985), our paper rationally evaluates the concepts and results developed over the past ten years in this field. It is grounded on a typology of two types of models: the first is based on users' anticipatory behaviour, and the second, on the collaborative behaviour of existing firms. The article initially discusses the specificity of network technologies, then analyses market standardisation models, and finally, studies the different actors models. Our conclusion builds upon existing works in network technologies. We next propose a research agenda     

Performance analysis for three pillars of sustainability

Journal of Productivity Analysis - Gross domestic product (GDP) has come under criticism as the only objective that countries should pursue for societal well-being. In this paper we apply an...     

Evaluating the TRQ Import Licensing Mechanisms in the Canadian Chicken Industry

Tariff rate quotas (TRQs) were introduced at the end of the Uruguay Round to support market access following the tariffication of nontariff barriers to trade in agriculture. The allocation of import licenses under the TRQ regime in the Canadian chicken industry is currently made according to discretionary criteria. The welfare properties of this import licensing scheme are evaluated in comparison with a less discretionary allocation method such as first-come, first-served (FCFS) using a numerical model. The analysis also provides a welfare evaluation of both methods as the current minimum access commitment for chicken imports is expanded. It is found that total welfare in the Canadian chicken industry is likely to be higher under a TRQ administration method based on nondiscretionary criteria such as firstcome, first-served. However, particular assumptions about the chicken producers'response to increased foreign competition can reverse this finding. Moreover the welfare differences between the two license administration schemes are less important when market access to imports is substantial.     

Fluctuations and response in financial markets: the subtle nature of ‘random’ price changes

Using trades and quotes data from the Paris stock market, we show that the random walk nature of traded prices results from a very delilcated interplay between two opposite tendencies: long-range correlated market orders that lead to super-diffusion (or persistence), and mean revrting limit orders that lead to sub-diffusion (or anti-persistence). We define and study a model where the price, at any instant, is the result of the impact of all past trades, mediated by a non-constant ‘propagator’ in time that describes the response of the market to a single trade. Within this model, the market is shown to be, in a precise sense, at a critical point, where the price is purely diffusive and the average response function almost constant. We find empirically, and discuss theoretically, a fluctuation-response relation. We also discuss the fraction of truly informed market orders, that correctly anticipate short-term moves, and find that it is quite small.