Convergence of some random functionals of discretized semimartingales

In this paper, we study the asymptotic behavior of sums of functions of the increments of a given semimartingale, taken along a regular grid whose mesh goes to 0. The function of the $i$th increment may depend on the current time, and also on the past of the semimartingale before this time. We study the convergence in probability of two types of such sums, and we also give associated central limit theorems. This extends known results when the summands are a function depending only on the increments, and this is motivated mainly by statistical applications.Comment: 31 page

The economy-wide effects of further trade reforms in Tunisia's services sectors

The purpose of this paper is to benchmark Tunisia against other emerging economies in terms of the regulatory barriers affecting particular services sectors, and to assess the economy-wide effects of further liberalizing these services trade restrictions, compared with reducing the dispersion in barriers to its merchandise trade. On the basis of a rather restricted sample of services sectors, partial regulatory reform would yield gains roughly equivalent to full unilateral reform of manufacturing tariffs, but roughly one-tenth the gains from full bilateral reform of border protection in agriculture with the European Union. The adjustment costs associated with these services trade reforms would be minimal. The paper identifies the reasons why the gains from these services reforms are relatively small, and argues that a wider set of reforms could provide win-win outcomes and even fewer adjustment costs. By contrast, the gains in agriculture and manufacturing tend to come at the expense of domestic output in the reforming sectors -- the gains are greater, but so too are the adjustment costs.Transport Economics Policy&Planning,Banks&Banking Reform,Emerging Markets,Economic Theory&Research,Markets and Market Access

tail behavior of a threshold autoregressive stochastic volatility model

We consider a threshold autoregressive stochastic volatility model where the driving noises are sequences of iid regurlarly random vatiables. We prove that both the right and the left tails of the marginal distribution of the log-volatility process are regularly varying with tail exponent. We also determine the exact values of the coefficients in the tail of the considered process.Stochastic volatility processes – Threshold – Tail distribution

The Demand for Eastern Oysters, Crassostrea virginica, from the Gulf of Mexico in the Presence of Vibrio vulnificus

California, in response to health concerns, initiated a program on 1 March 1991 which required anyone selling eastern oysters, Crassostrea virginica, from the Gulf of Mexico area to notify potential consumers that there was a risk in consuming them raw. This mandatory warning, followed shortly thereafter by a similar warning in other states, including Louisiana and Florida, received extensive press cover-age throughout the country and particularly in the Gulf area. This paper examines the extent to which the demand for Gulf-area oysters has been reduced as a result of mandatory warning labels and negative publicity. In general, the results suggest that since 1991 the “summer” dockside price has been reduced by about 50% as a result of warning labels and associated negative publicity, while the “winter” dockside price has been reduced by about 30%

Asymptotic Behavior for the Extreme Values of a Linear Regression Model

We consider a class of linear regression model with extreme distribution noise. We show by a mean of point process technique that the asymptotic distribution of the maximum is the same as the one of the max of the noise process, under specific conditions.Extreme value theory – Poisson random process – Point process – regression model.

Trade reforms, farm productivity, and poverty in Bangladesh

This paper analyzes the distributional impacts of trade reforms in rural areas of Bangladesh. The liberalization of trade in irrigation equipment and fertilizer markets during the early 1990s has led to structural changes in the agricultural sector and a significant increase in rice productivity. A resulting increase in output has been associated with a decline in producer and consumer rice prices of approximately 25 percent. Using a combination of ex-post and ex-ante approaches, the authors investigate the implications of the changes in rice productivity and prices for the welfare of households. They find that the net effects of increased rice productivity and lower rice prices have benefited the poor. Regardless of the particular category analyzed, the poorest households emerged as being particularly positively affected by reforms in the 1990s. This mainly reflects the fact that they are predominantly net rice buyers in both urban and rural markets. In contrast, large net sellers of rice, among the better-off households in the rural areas, were the main losers. Since net buyers in rural areas tend to be poorer than net sellers, trade liberalization has benefited the poor. Although the authors are not able to test empirically what has happened to the welfare level of agricultural wage earners, secondary evidence suggests that they have gained from trade liberalization.Rural Poverty Reduction,Economic Theory&Research,Markets and Market Access,Crops&Crop Management Systems

Selecting source image sensor nodes based on 2-hop information to improve image transmissions to mobile robot sinks in search \& rescue operations

We consider Robot-assisted Search $\&$ Rescue operations enhanced with some fixed image sensor nodes capable of capturing and sending visual information to a robot sink. In order to increase the performance of image transfer from image sensor nodes to the robot sinks we propose a 2-hop neighborhood information-based cover set selection to determine the most relevant image sensor nodes to activate. Then, in order to be consistent with our proposed approach, a multi-path extension of Greedy Perimeter Stateless Routing (called T-GPSR) wherein routing decisions are also based on 2-hop neighborhood information is proposed. Simulation results show that our proposal reduces packet losses, enabling fast packet delivery and higher visual quality of received images at the robot sink