An Art-Historical Paradigm for Investigating Native American Pictographs of the Lower Pecos Region, Texas

In the shadows of deep canyons in Southwest Texas and Northern Mexico, where the Pecos, Devils, and Rio Grande flow, are thousands of paintings on the walls of hundreds of rockshelters and overhangs. Archaeologists term such works pictographic rock art. These particular pictographs were created over many centuries by Native American groups known collectively today as the Lower Pecos Region cultures

Commentary on "Arbitrage-free bond pricing with dynamic macroeconomic models"

Bonds - Prices ; Macroeconomics

Inflation, financial markets and capital formation - commentary

Capital ; Financial markets ; Inflation (Finance)

The outcome of different bargaining models: the effects on wages, employment and the employment mix

The paper analyses data on wages, employment and labour composition in the Uruguayan manufacturing sector during 1985-1999 in order to get some evidence on the effects of union action on these variables. The whole period is first studied using a model in which no assumptions on the underlying bargaining model are made. The results support the hypothesis of two different bargaining frameworks in the 80s and 90s. Therefore, a right-tomanage bargaining model is specified for the 80s and a recursive contracts model for the 90s. Union effects are such that while in the 80s the effect of trade unions were to increase wages and hence decrease employment, in the nineties they moderated wage demands in exchange of more job stability. They not only managed to have a positive direct effect on employment but also to buffer the negative effects of increased openness and demand fluctuations on employment. The existence of unions also had an impact on labour composition, favouring a higher share of non-production workers in total employment. The result can be linked to the fact that firms moved to more capital intensive – or at least more skilled labour intensivetechnologies to avoid union costs. A final finding is related to the fact that the change in the Uruguayan bargaining regime at the beginning of the 90s – by which the mandatory extension of contracts vanished – favoured a more decentralised negotiation scheme and thus ended with the homogenous impact found in the 80s, since coordination in bargaining was lost.

Optimal trading algorithms and selfsimilar processes: a p-variation approach

Almgren and Chriss ("Optimal execution of portfolio transactions", Journal of Risk, Vol. 3, No. 2, 2010, pp. 5-39) and Lehalle ("Rigorous strategic trading: balanced portfolio and mean reversion", Journal of Trading, Summer 2009, pp. 40-46.) developed optimal trading algorithms for assets and portfolios driven by a brownian motion. More recently, Gatheral and Schied ("Optimal trade execution under geometric brownian motion in the Almgren and Chriss framework", Working paper SSRN, August 2010) addressed the same problem for the geometric brownian motion. In this article we extend these ideas for assets and portfolios driven by a discrete version of a selfsimilar process of exponent H in (0,1), which can be either a fractional brownian motion of Hurst exponent H or a truncated Lévy distribution of index 1/H. The cost functional we use is not the classical expectation-variance one: instead of the variance, we use the p-variation, i.e. the Lp equivalent of the variance. We find explicitly the trading algorithm for any p>1 and compare the resulting trading curve (that we call p-curve) with the classical expectation-variance curve (the 2-curve). If p2 then the p-curve is above the 2-curve at the beginning of the execution and below at the end. Therefore, this pattern minimizes the market impact. We also show that the value of p in the p-variation is related to the exponent H of selfsimilarity via p=1/H. In consequence, one can find the right value of p to put into the trading algorithm by calibrating the exponent H via real time series. We believe this result is interesting applications for high-frecuency trading.

Optimal algorithmic trading and market microstructure

The efficient frontier is a core concept in Modern Portfolio Theory. Based on this idea, we will construct optimal trading curves for different types of portfolios. These curves correspond to the algorithmic trading strategies that minimize the expected transaction costs, i.e. the joint effect of market impact and market risk. We will study five portfolio trading strategies. For the first three (single-asset, general multi-asseet and balanced portfolios) we will assume that the underlyings follow a Gaussian diffusion, whereas for the last two portfolios we will suppose that there exists a combination of assets such that the corresponding portfolio follows a mean-reverting dynamics. The optimal trading curves can be computed by solving an N-dimensional optimization problem, where N is the (pre-determined) number of trading times. We will solve the recursive algorithm using the "shooting method", a numerical technique for differential equations. This method has the advantage that its corresponding equation is always one-dimensional regardless of the number of trading times N. This novel approach could be appealing for high-frequency traders and electronic brokers.quantitative finance; optimal trading; algorithmic trading; systematic trading; market microstructure

The determinants of the quality of Sales-Marketing Interface in a Multinational Customer Brand Focused Company: The Latin American Branches

Customer evolution and changes in consumers, determine the fact that the quality of the interface between marketing and sales may represent a true competitive advantage for the firm. Building on multidimensional theoretical and empirical models developed in Europe and on social network analysis, the organizational interface between the marketing and sales departments of a multinational high-growth company with operations in Argentina, Uruguay and Paraguay is studied. Both, attitudinal and social network measures of information exchange are used to make operational the nature and quality of the interface and its impact on performance. Results show the existence of a positive relationship of formalization, joint planning, teamwork, trust and information transfer on interface quality, as well as a positive relationship between interface quality and business performance. We conclude that efficient design and organizational management of the exchange network are essential for the successful performance of consumer goods companies that seek to develop distinctive capabilities to adapt to markets that experience vertiginous change

Technology challenges for space interferometry: the option of mid-infrared integrated optics

Nulling interferometry is a technique providing high angular resolution which is the core of the space missions Darwin and the Terrestrail Planet Finder. The first objective is to reach a deep degree of starlight cancelation in the range 6 -- 20 microns, in order to observe and to characterize the signal from an Earth-like planet. Among the numerous technological challenges involved in these missions, the question of the beam combination and wavefront filtering has an important place. A single-mode integrated optics (IO) beam combiner could support both the functions of filtering and the interferometric combination, simplifying the instrumental design. Such a perspective has been explored in this work within the project Integrated Optics for Darwin (IODA), which aims at developing a first IO combiner in the mid-infrared. The solutions reviewed here to manufacture the combiner are based on infrared dielectric materials on one side, and on metallic conductive waveguides on the other side. With this work, additional inputs are offered to pursue the investigation on mid-infrared photonics devices.Comment: Accepted in Adv. in Space Researc

The impact of unions on the economic performance of firms

This study examines the impact of unionization at the industry level and of the degree of centralization in bargaining – the industry or the firm - on wages and on the economic performance of firms within the manufacturing sector in Uruguay, using a panel of establishments for the period 1988-1995. The model, estimated using the Generalized Method of Moments, used controls for the degree of exposure to international and regional competition, and a set of industry and firm characteristics. The main findings point at unionization increasing wages and employment; promoting investment due to the firms substituting labor by capital; being organized in those plants with higher rate of profits, but promoting increases in productivity and preventing profitability increases. Given the negative effect of unionization at the industry level on the rate of growth of profitability of firms, results also suggest that unions tended to organize and to be stronger in those sectors in which extra rents were higher due to monopoly power. The evidence also points at firm-level negotiations taking into account the interests of both parties – workers and managers - so that enhanced productivity and probably survival were achieved together with lower rates of wage inflation; substitution of labor by capital and lower profits.