Imperfect Competition, General Equilibrium and Unemployment

We analyze whether different learning abilities of firms with respect to general equilibrium effects lead to different levels of unemployment. We consider a general equilibrium model where firms in one sector compete à la Cournot and a real wage rigidity leads to unemployment. If firms consider only partial equilibrium effects when choosing quantities, the observation of general equilibrium feedback effects will lead to repeated quantity adjustments until a steady state is reached. When labor is im mobile across industries, unempolyment in the steady state is lower than when all general equilibrium effects are incorporated at once. The opposite result is true if labor is mobile.Product markets, Cournot competition, learning of general equilibrium effects, unemployment

Fracture Toughness and Duration of Load Factor II. Duration Factor for Cracks Propagating Perpendicular-to-Grain

Dead load tests of notched beams of Douglas-fir with the crack plane parallel-to-grain and the propagation direction of the crack perpendicular-to-grain showed that presently used duration of load factors can be used for this type of loading. A decrease in strength with increasing duration was observed, but the effect was less than in unnotched beams. Ramp loading tests of messmate stringybark and Douglas-fir notched beams showed increased loads at crack initiation at slower load rates. In messmate stringybark this increase was not statistically significant, but was found significant in Douglas-fir. These results suggest that stress redistribution is taking place around the notch tip, and that a duration of load factor need not be applied to this particular system

Strength and Related Properties of Bishop Pine I. Strength of "Blue Race" Bishop Pine from Three Locations

Tests were made of mechanical properties, according to ASTM methods D143-52, of "Blue Race" Bishop pine from locations in Mendocino and Humboldt counties in California. Bishop pine was found to be equal in strength to coast-type Douglas-fir in some respects (modulus of rupture values at 12% moisture content of 12,900 and 12,400 psi, respectively, for Bishop pine and Douglas-fir) but to be more like ponderosa pine in other respects (maximum crushing strength parallel-to-grain at 12% moisture content of 5,540 and 5,320 psi, respectively, for Bishop pine and ponderosa pine). There were significant differences in strength according to location, which appeared to be due to site conditions rather than geographical location

Prediction of Creep in Plywood Part I. Prediction Models for Creep in Plywood

Three models for predicting creep in plywood from measured constituent properties were formulated using phenomenological linear viscoelastic theory. The three models represent a one-dimensional, quasi-elastic solution, a two-dimensional, quasi-elastic solution, and a two-dimensional, viscoelastic solution. In part II of this study, the models will be used to compute the principal components of the two-dimensional creep compliance tensor for plywood and will show that predictions of creep behavior based on all three solutions give similar results. The most accurate prediction of parallel and perpendicular creep was made with the one-dimensional model

Further Experiments on Creep-Rupture Life Under Cyclic Environmental Conditions

An increase in beam size from 10 by 20 mm to 2 by 2 inches increased the mean time to failure at a load level of 70% of modulus of rupture of specimens subjected to moisture content cycling by more than one order of magnitude. The effect of temperature cycling appears to depend on moisture content. The results indicate that the present load duration factor for wood is adequate under normal conditions, but that adjustments are needed when loaded members are small or when there are severe cyclic changes in ambient conditions

Strength and Related Properties of Knobcone Pine

The mechanical properties of knobcone pine (Pinus attenuata Lemm.) were evaluated using the second 8-ft log from the butt of ten trees selected from a stand in Siskiyou County, California. The trees, averaging 71 ft in height and 14 in. dbh, had a growth rate of 12 rings per inch at the stump and a specific gravity of 0.38, based on green volume and oven-dry mass. Specimens were selected and tested in accordance with ASTM D143-52 in both green and air-dry conditions. Adjusted to 12% moisture content, knobcone pine has a modulus of rupture and modulus of elasticity in static bending of 10,800 psi and 1,500,000 psi, respectively, a maximum crushing strength parallel-to-grain of 5,640 psi, and a shear strength parallel-to-grain of 980 psi. These results show that knobcone pine is similar to ponderosa pine in strength and stiffness

Fracture Toughness and Duration of Load Factor I. Six Principal Systems of Crack Propagation and the Duration Factor for Cracks Propagating Parallel to Grain

Critical stress intensity factors for air-dry Douglas fir were found to be 2200, 2450, 281, 373, 323, and 323 psi ínch for the LT, LR, TL, RL, TR, and RT systems, respectively, where the first letter indicates the direction normal to the crack plane and the second the direction of crack propagation. Long-term load tests with notched beams showed that for the TL system the load duration factor was similar to that applying to modulus of rupture. Moisture changes significantly reduced the mean time to failure of notched beams under dead loads as compared to tests under constant moisture conditions

Imperfect competition in product markets and labor markets, general equilibrium and unemployment

In this thesis it is analyzed if promoting product market competition can help to to fight unemployment in Europe. We have used a general equilibrium model in order to study how reducing mark-ups and increasing productivity in one sector affect aggregate unemployment for an exogenously given minimum real wage. The bottom-line was that product market reforms will help to reduce aggregate unemployment under most circumstances. Modeling a microfoundation of mark-ups, we have demonstrated that different learning abilities of firms with respect to general equilibrium effects lead to different levels of unemployment. If firms, competing a la Cournot, consider only partial equilibrium effects when choosing quantities, the observation of general equilibrium feedbacks will lead to repeated quantity adjustments until a steady state is reached. We have used the above model to show that the impacts of mergers of firms on employment are rather negative. We then have examined wage bargaining between employers and labor unions. We have demonstrated that if agents do hardly consider general equilibrium effects, low real wages and low unemployment results. With an intermediate view, when partial equilibrium effects are taken into account, high real wages and unemployment results. If all general equilibrium effects are incorporated at once, again low real wages and low unemployment results. We thus have obtained a hump-shaped relationship between the extend of feedback effects incorporated by the bargaining parties and real wages or unemployment. Finally the impacts of uneven productivity improvements on employment were shown to generally remain positive when wages are set endogenously by wage bargaining