Profit and Cost in "Modern" Post-Marxian Profit Theory: A Case Study from Varian's "Intermediate Microeconomics"

In this paper, I examine the treatment of competitive profit of professor Varian in his textbook on Microeconomics, as a representative of the “modern” post-Marxian view on competitive profit. I show how, on the one hand, Varian defines profit as the surplus of revenues over cost and, thus, as a part of the value of commodities that is not any cost. On the other hand, however, Varian defines profit as a cost, namely, as the opportunity cost of capital, so that, in competitive conditions, the profit or income of capital is determined by the opportunity cost of capital. I argue that this second definition contradicts the first and that it is based on an incoherent conception of opportunity cost.

Employment comovements at the sectoral level over the business cycle

This paper extends the technique suggested by den Haan (2000) to investigate contemporaneous as well as lead and lag correlations among economic data for a range of forecast horizons. The technique provides a richer picture of the economic dynamics generating the data and allows one to investigate which variables lead or lag others and whether the lead or lag pattern is short term or long term in nature. The technique is applied to monthly sectoral level employment data for the U.S. and shows that among the ten industrial sectors followed by the U.S. Bureau of Labor Statistics, six tend to lead the other four. These six have high correlations indicating that the structural shocks generating the data movements are mostly in common. Among the four lagging industries, some lag by longer intervals than others and some have low correlations with the leading industries indicating that these industries are partially influenced by structural shocks beyond those generating the six leading industries.

Profit as Cost versus Profit as Surplus over Cost: A Case Study on Varian's "Intermediate Microeconomics"

On the analysis of Varian’s textbook on Microeconomics, which I take to be a representative of the standard view, I argue that Varian provides two contrary notions of profit, namely, profit as surplus over cost and profit as cost. Varian starts by defining profit as the surplus of revenues over cost and, thus, as the part of the value of commodities that is not any cost; however, he provides a second definition of profit as a cost, namely, as the opportunity cost of capital. I also argue that the definition of competitive profit as the opportunity cost of capital involves a self-contradictory notion of opportunity cost.

Second-best tax policy in a growing economy with externalities

This paper investigates the exploitation of environmental resources in a growing economy within a second-best scal policy framework. Agents derive utility from two types of consumption goods one which relies on an environmental input and one which does not as well as from leisure and from environmental amenity values. Property rights for the environmental resource are potentially incomplete. We connect second best policy to essential components of utility by considering the elasticity of substitution among each of the four utility arguments. The results illustrate potentially important relationships between environmental amentity values and leisure. When amenity values are complementary with leisure, for instance when environmental amenities are used for recreation, taxes on extractive goods generally increase over time. On the other hand, optimal taxes on extractive goods generally decrease over time when leisure and environmental amenity values are substitutes. Unders some parameterizations, complex dynamics leading to nonmonotonic time paths for the state variables can emerge.

Scenario Cluster Lagrangian Decomposition in two stage stochastic mixed 0-1 optimization

In this paper we introduce four scenario Cluster based Lagrangian Decomposition (CLD) procedures for obtaining strong lower bounds to the (optimal) solution value of two-stage stochastic mixed 0-1 problems. At each iteration of the Lagrangian based procedures, the traditional aim consists of obtaining the solution value of the corresponding Lagrangian dual via solving scenario submodels once the nonanticipativity constraints have been dualized. Instead of considering a splitting variable representation over the set of scenarios, we propose to decompose the model into a set of scenario clusters. We compare the computational performance of the four Lagrange multiplier updating procedures, namely the Subgradient Method, the Volume Algorithm, the Progressive Hedging Algorithm and the Dynamic Constrained Cutting Plane scheme for different numbers of scenario clusters and different dimensions of the original problem. Our computational experience shows that the CLD bound and its computational effort depend on the number of scenario clusters to consider. In any case, our results show that the CLD procedures outperform the traditional LD scheme for single scenarios both in the quality of the bounds and computational effort. All the procedures have been implemented in a C++ experimental code. A broad computational experience is reported on a test of randomly generated instances by using the MIP solvers COIN-OR and CPLEX for the auxiliary mixed 0-1 cluster submodels, this last solver within the open source engine COIN-OR. We also give computational evidence of the model tightening effect that the preprocessing techniques, cut generation and appending and parallel computing tools have in stochastic integer optimization. Finally, we have observed that the plain use of both solvers does not provide the optimal solution of the instances included in the testbed with which we have experimented but for two toy instances in affordable elapsed time. On the other hand the proposed procedures provide strong lower bounds (or the same solution value) in a considerably shorter elapsed time for the quasi-optimal solution obtained by other means for the original stochastic problem.

Cell microencapsulation for therapeutic purposes: towards greater control over biocompatibility

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[R_SanMillan_Yuso] Documentación geométrica de las excavaciones arqueológicas realizadas en el Monasterio de Yuso (San Millán de la Cogolla, La Rioja)

[ES] El seguimiento arqueológico se realiza sobre las capillas del la nave Norte de la iglesia más la capilla “de las reliquias”, en total 9 capillas de unos 10 x 10 metros cada una. Los elementos a documentar son las unidades estratigráficas exhumadas que, en gran medida corresponden a enterramientos (fosas y los propios esqueletos).

Extended ageing time and temperature effects on quality of sub-primal cuts of boxed beef

[EN]Most of the information indicating ageing improves tenderness has been collected on the loin and rib-eye muscles over relatively short ageing times, assuming that all muscles will react similarly. In the present study, the effect of extended ageing times on instrumental texture (56 d) and sensory characteristics (42 d) of six different beef sub-primals [striploin (SL), inside round (IR), outside round (OR), eye of round (ER), blade eye (BE) and chuck tender (CT)] was studied. The effects of two ageing temperatures (1and 58C) were also compared. In general, ageing increased tenderness (P<0.05) of SL, BE, ER and CT sub-primals, although BE shear force increased after 42 d of ageing. On the other hand, ageing had no effect on IR tenderness (P<0.05) and resulted in a decrease in tenderness of OR (P<0.05) until day 35, with a later increase after 42 d of ageing. Increasing ageing temperature (58C) had limited effect on tenderness, but ageing time and temperature increases led to lower flavour and higher off-flavour intensity (P<0.05) of the studied sub-primals. These results suggest that cutspecific maximum ageing times and rigid adherence to temperature maximums would be of benefit to optimize postslaughter processes and meat quality

Dialog Systems based on Markov decision processes over two real tasks

In this work the state of the art of the automatic dialogue strategy management using Markov decision processes (MDP) with reinforcement learning (RL) is described. Partially observable Markov decision processes (POMDP) are also described. To test the validity of these methods, two spoken dialogue systems have been developed. The first one is a spoken dialogue system for weather forecast providing, and the second one is a more complex system for train information. With the first system, comparisons between a rule-based system and an automatically trained system have been done, using a real corpus to train the automatic strategy. In the second system, the scalability of these methods when used in larger systems has been tested.

Dynamics of Streptococcus pneumoniae Serotypes Causing Acute Otitis Media Isolated from Children with Spontaneous Middle-Ear Drainage over a 12-Year Period (1999–2010) in a Region of Northern Spain

10 p.

Increased physical activity is not enough to recover astrocytic population from dark-rearing. Synergy with multisensory enrichment is required

10 p.

The long road of climate negotiations: From Kyoto to Paris stopping over in Doha

4 p.

Breaking the 400 ppm barrier: Physical and Social implications of the recent CO2 rise

6 p.

Rompiendo la barrera de las 400 ppm: implicaciones físicas y sociales del reciente aumento de CO2

6 p.

400 ppm-ko langa hautsi da: CO2-kontzentrazioaren igoeraren ondorio fisiko eta sozialak

6 p.