Endogenous Quantity Research Articles

On the effects of supplier encroachment under endogenous quantity leadership

On the effects of supplier encroachment under endogenous quantity leadership

Money is a right: Alfred Lansburgh’s Token Theory of Money

Alfred Lansburgh was a leading publicist on money in Germany during the Weimar Republic. He developed a Token Theory of Money, a nominalistic monetary theory with an endogenous quantity of money but warns of the danger of misuse. Only therefore, he combines his understanding of money as a right—as a legal claim on goods and services—with a metallistic conception of gold money. Lansburgh was misunderstood during his time, and he remains so until today. He was often described as an “orthodox gold money theorist,” but he was a passionate “token money theorist,” with many similarities e.g. to Joseph Schumpeter.

Determinants of Onion Marketed Among Smallholder Producers in Gemechis District, West Hararghe Zone, Oromia National Regional State of Ethiopia

Onion plays a crucial role in enhancing food security and generates income for the smallholder farmers of Ethiopia. This paper was attempted to analyze the determinants of onion supplied to the market in Gemechis District, Oromia Region of Ethiopia. Data for the study were collected from both primary and secondary sources. The primary data were collected by household survey using a pre-tested structured questionnaire and key informant interview using checklists. The data were collected from 176 farmers. The collected data was analyzed using both descriptive statistics and econometric model. The descriptive statistics was used to analyze the socio-economic characteristics of smallholder farmers and econometric model was used to determine the factors affecting onion supplied to the market. The results of two-stage least square regression model showed that quantity of onion supplied to the market was significantly and positively influenced by the endogenous quantity of onion produced. In addition, distance from nearest market, non/off farming income, land allocated and lagged price significantly affect the onion marketed. The study findings suggest the need to improve rural road infrastructure, intensification of land to compensate through cash crop production and efficient utilization of the existing limited farm land and encourage investment on off/non-farm incomes as well as onion production.

Amount of Progesterone Consumed Based on Varying Fat Concentrations, Dietary Recommendations, and Estimated Safe Levels in Commercial Cow Origin Liquid Dairy Products.

Federal guidelines recommend that food with hormone content fall below 1% of endogenous production in the subset of the population with the lowest daily production. The majority of dairy products are obtained from pregnant cows, which increase the level of hormones present. The purpose of this article was to perform theoretical evaluation of the quantity of progesterone in cow's milk based on fat percentages and to assess whether this was within the recommended range. Daily recommended dairy product intake from various countries worldwide was researched. This was compared to the concentration of progesterone previously identified in varying fat contents of cow origin milk to assess the amount of progesterone (mg/day) that would be consumed if the guidelines were followed. The maximum daily progesterone consumption suggested will be met by ingestion of 2.7 L, 1.42 L, 1.13 L, 940 mL, 810 mL, 650 mL of 0% (skim), 1%, 2%, 3.25%, 10% (cream), and 35% (whipping cream) fat liquid cow origin dairy product, respectively. Therefore, ingestion of the highest amount of recommended daily dairy intake fell below 1% of the daily endogenous quantity produced, except in the unlikely case of consumption of 650 mL of 35% fat. Studies demonstrating an effect of cow's liquid dairy product intake may need to be revisited, since levels of progesterone consumption remain within the recommended levels. However, it should be considered that ingestion of cow's milk might have a potential effect on the hormonal profile in patients; however, this seems unlikely.

Target exposure and pharmacodynamics study of the indoleamine 2,3-dioxygenase-1 (IDO-1) inhibitor epacadostat in the CT26 mouse tumor model

Indoleamine-2,3-dioxygénase (IDO1) is an enzyme which converts tryptophan (Trp) into kynurenine (Kyn). Having a critical role in tumor immune escape by decreasing Trp and increasing Kyn levels in the microenvironment, IDO1 was one of the first targets for small molecules drug discovery in the field of immuno-oncology. A potent and selective IDO1 inhibitor such as Epacadostat (EPA) was shown to enhance the antitumor activity by restoring the immune system fitness. As exposure at the site of action and to its specific target are identified as the most important factors for success in drug discovery, the objective of this study was to explore the target exposure and intra-tumor pharmacodynamics effects of EPA drug on the tumor metabolism. To do so, we used both Quantitative Mass Spectrometry Imaging (QMSI) and liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) technologies in order to monitor drug and metabolites distribution and their endogenous quantity in the CT26 mouse tumor model. Target exposure analysis showed that almost 61% of EPA signal (26 μg/g) was concentrated within 38% of the entire tumor surface. Semi quantitative analysis of this region confirmed a positive correlation between IDO1 expression and EPA concentration. In parallel, pharmacodynamics analysis highlighted a response efficacy through Kyn/Trp ratio calculation that was shown decreasing after EPA treatment as noticed in treated CT26 tumors (−82%), plasma (−63%) and blood (−62%) compared to control samples. Finally, 15% and 85% of Kyn signal was found in regions with high and low EPA, respectively. In this study, using QMSI, we went further than only quantifying the metabolites and the drug, by estimating the pharmacological effect efficacy of the drug through a target exposure study handled in different regions of the tumor either expressing IDO1 or Kyn.

Regulatory Inspection Regimes and Oligopoly Competition

To enforce compliance with product safety standards, regulatory agencies employ supervisors to conduct inspections and impose fines on firms that violate these standards. In most industries, the designated regulators choose between various inspection regimes, such as announced or unannounced surprise inspections. We conduct a positive analysis of the impact of these regimes on firms' safety choices in a multiple stage oligopoly game with endogenous quality and quantity competition. In equilibrium, whether surprise inspections achieve a higher level of safety depends on the number of firms, the cost of safety provision and demand. Furthermore, the impact on safety of increasing the fine, the supervisor's wage or the probability of inspections may be non-monotonic and also depends on market size and structure. Finally, we show that in some cases, neither unannounced, nor announced inspections can attain the socially optimal safety level. However in such cases, unannounced inspections minimize the distortion from socially optimal safety.

Overcompliance with endogenous environmental standards and quantity competition

We propose a model of environmental overcompliance where firms set the environmental quality of their products and compete in quantities, while the government imposes an environmental standard with the aim to maximise welfare. We show that all firms overcomply if the environmental impact of production is sufficiently low, otherwise unilateral overcompliance emerges by the firm with higher environmental quality. With price competition, the introduction of an environmental standard quality always brings about unilateral overcompliance.

Eliminating the Outside Good Bias in Logit Models of Demand with Aggregate Data

AbstractThe logit model is the most popular tool in estimating demand for differentiated products. In this model, the outside good plays a crucial role because it allows consumers to stop buying the differentiated good altogether if all brands simultaneously become less attractive (e.g. if a simultaneous price increase occurs). But practitioners lack data on the outside good when only aggregate data are available. The currently accepted procedure is to assume a “market potential” that implicitly defines the size of the outside good (i.e. the number of consumers who considered the product but did not purchase); in practice, this means that an endogenous quantity is approximated by a reasonable guess thereby introducing the possibility of an additional source of error and, most importantly, bias. We provide two contributions in this paper. First, we show that structural parameters can be substantially biased when the assumed market potential does not approximate the outside option correctly. Second, we show how to use panel data techniques to produce unbiased structural estimates by treating the market potential as an unobservable in both the simple and the random coefficients logit demand model. We explore three possible solutions: (a) controlling for the unobservable with market fixed effects, (b) specifying the unobservable to be a linear function of product characteristics, and (c) using a “demeaned regression” approach. Solution (a) is feasible (and preferable) when the number of goods is large relative to the number of markets, whereas (b) and (c) are attractive when the number of markets is too large (as in most applications in Marketing). Importantly, we find that all three solutions are nearly as effective in removing the bias. We demonstrate our two contributions in the simple and random coefficients versions of the logit model via Monte Carlo experiments and with data from the automobile and breakfast cereals markets.

Estrone and Estrone Sulfate Concentrations in Milk and Milk Fractions

Dairy products naturally contain estrogens, and some consumer groups contend these estrogens cause adverse health effects. The objectives of this research were to characterize estrone (E1) and estrone sulfate (E1S) concentrations in milk from a large number of individual cows, in skim and fat fractions of milk, and in retail milk to provide food and nutrition practitioners with information to estimate potential consumption. Milk was from Holstein cows. Data are presented as means and standard deviations. Analysis of variance was used to determine differences in E1 and E1S content of whole milk and its skim and fat fractions. Mean E1 and E1S concentrations (n=173 cows) were 7.0±12.7 and 46.7±62.1 pg/mL (25.89±46.96 and 172.74±229.71 pmol/L), respectively. Analysis of milk fractions (n=50 samples) demonstrated that 55% of E1 and 14% of E1S were associated with the fat fraction with the remainder associated with the skim fraction. Concentrations of E1 and E1S in pasteurized-homogenized whole milk (n=8) averaged 10.3±0.6 and 85.9±7.3 pg/mL (38.09±2.22 and 317.74±27.00 pmol/L), respectively. Production rates of E1 plus estradiol in human beings range from 54,000 to 630,000 ng/day. US Food and Drug administration guidelines state that no physiologic effects occur when consumption is ≤1% of the endogenous quantities produced by the segment of the population with the lowest daily production. This threshold value for intake would be 540 ng/day. Estimated total E1 intake from three servings of whole milk was 68 ng/day, which represents 0.01% to 0.1% of daily production rates in human beings. These findings support levels below the current guidelines for safe consumption.

Eliminating the Outside Good Bias in Logit Models of Demand with Aggregate Data

The logit model is the most popular tool in estimating demand for differentiated products. In this model, the outside good plays a crucial role because it allows consumers to stop buying the differentiated good altogether if all brands simultaneously become less attractive (for example if a simultaneous price increase occurs). But practitioners lack data on the outside good when only aggregate data is available. The currently accepted procedure is to assume a “market potential” that implicitly defines the size of the outside good (i.e. the number of consumers who considered the product but did not purchase); in practice, this means that an endogenous quantity is approximated by a reasonable guess thereby introducing the possibility of an additional source of error and, most importantly, bias. We provide two contributions in this paper. First, we show that structural parameters can be substantially biased when the assumed market potential does not approximate the outside option correctly. Second, we show how to use panel data techniques to produce unbiased structural estimates by treating the market potential as a fixed effect (known as a “correlated random effect” in the non-linear panel data literature). We explore three possible solutions: a) controlling for the unobservable with market fixed effects, b) specifying the unobservable to be a linear function of the (average) product characteristics, and c) a “demeaned” regression approach. Solution a) is feasible (and preferable) when the number of goods is large relative to the number of markets, whereas b) and c) are attractive when the number of markets is too large. Importantly, we find that all three solutions are nearly as effective in removing the bias. We demonstrate our two contributions in the simple and random coefficients versions of logit via Monte Carlo experiments and with data from the automobile and breakfast cereals markets.

Simultaneous vs. sequential price competition with incomplete information

We compare equilibria with sequential and simultaneous moves under homogeneous-good Bertrand competition when unit costs are private information. Under an alternative interpretation, we examine the consequences of awarding a right of first refusal in a first-price procurement auction with endogenous quantity.

Enzymatic Pathways That Regulate Endocannabinoid Signaling in the Nervous System

Enzymatic Pathways That Regulate Endocannabinoid Signaling in the Nervous System

L-Arginine metabolism in dog kidney and isolated nephron segments

The renal basic amino acid metabolism often differs in rodents, strict carnivores, and omnivore species. Given the pivotal role of l-arginine and l-ornithine in several metabolic pathways and the fact that the dog is closely related to humans, being also an omnivore, we tested whether l-arginine metabolism and l-ornithine catabolism take place in the dog kidney. We examined the metabolism of l-arginine in dog cortical tubules to integrate local l-arginine metabolism into a general physiological and metabolic framework. To achieve these goals, we first ascertained the protein expression of relevant enzymes by Western blot. l-Arginine catabolism was studied in suspensions of canine cortical proximal tubules, medullary thick ascending limbs, and papillary collecting ducts either incubated without exogenous l-arginine being added (small endogenous quantities) or incubated with l-arginine being added in supraphysiological amounts (2 mmol/L with or without the presence of alternative metabolic substrates, 2 mmol/L l-glutamine, or lactate). The results revealed that dog kidneys consumed l-citrulline and released l-arginine and l-ornithine. Argininosuccinate synthetase and lyase, arginase II, and ornithine aminotransferase were detected in the renal cortex. Arginase II activity was found in a suspension of proximal tubules by measuring the amounts of urea and l-ornithine produced. A fraction of this l-ornithine was further partially metabolized through the intramitochondrial ornithine aminotransferase pathway, leading to changes in l-glutamate, glucose, l-alanine, and ammonia metabolism without l-proline accumulation. Medullary thick ascending limbs expressed a very low arginase activity, whereas papillary collecting ducts did not. In conclusion, the dog kidney produces l-arginine. Part of this l-arginine is further catabolized by arginase II, suggesting that its physiological role was to produce l-ornithine for the body.

Competing auctions with endogenous quantities

Two sellers decide on their discrete supply of a homogenous good. There is a finite number of buyers with unit demand and privately known valuations. In the first model, there is a centralized market place where a uniform auction takes place. In the second, there are two distinct auction sites, each with one seller, and buyers decide where to bid. Using the theory of potential games, we show that in the one-site auction model there is always an equilibrium in pure-strategies. In contrast, if the distribution of buyers values has an increasing failure rate, and if the marginal cost of production is relatively low, there is no pure-strategy equilibrium where both sellers make positive profits in the competing sites model. We also identify conditions under which an equilibrium with a unique active site exists. We deal with the finite and discrete models by using several results about order statistics developed by Richard Barlow and Frank Proschan [R. Barlow, F. Proschan, Mathematical Theory of Reliability, Wiley, New York, 1965; R. Barlow, F. Proschan, Inequalities for linear combinations of order statistics from restricted families, Ann. Math. Statist. 37 (1966) 1593–1601; R. Barlow, F. Proschan, Statistical Theory of Reliability and Life Testing, McArdle Press, Silver Spring, 1975].

Use of gas chromatographic-mass spectrometric techniques in studies of androst-16-ene and androgen biosynthesis in human testis; cytosolic specific binding of 5α-androst-16-en-3-one

Homogenates of histologically normal human testis from three men were incubated separately with pregnenolone, 16-dehydropregnenolone, 5alpha-pregnane-3,20-dione, 3beta-hydroxy-5alpha-pregnan-20-one and androsta-5,16-dien-3beta-ol (androstadienol) in the presence of NADPH in a study of androst-16-ene and androgen biosynthesis. After the addition of internal standards and initial extraction and purification, metabolites were identified using gas chromatography-mass spectrometry (GC-MS) and monitoring selectively for three principal ions in each case at the appropriate GC retention time. Quantification was achieved by comparison with calibration lines for authentic steroids, together with the appropriate internal standards, prepared by monitoring three ion fragments for each analyte. In all experiments, androstadienol was found to be the major androst-16-ene metabolite of pregnenolone (seven times the control, i.e. endogenous, quantity; 19.8 +/- 3 ng/100 mg homogenate protein, mean +/- SEM, n = 9). Pregnenolone was also converted to androsta-4,16-dien-3-one (androstadienone) with three times the endogenous quantity (44 +/- 10 ng/100 mg homogenate protein, mean +/- SEM, n = 9) being formed. The formation of testosterone occurred only in trace amounts in the incubations of testis taken from one man (a 69-yr-old) but appreciable yields (six times endogenous levels 90 +/- 7 ng/100 mg homogenate protein, mean +/- SEM, n = 9) were found with testes from two younger men. Only traces of 5alpha-dihydrotestosterone were detected. Using androstadienol as the substrate, androstadienone was shown to be the major metabolite (approximately 10 times greater than control incubations) together with 5alpha-androst-16-en-3alpha- and 3beta-ols at approximately twice the endogenous quantities (5 ng/100 mg homogenate protein). In some incubations with androstadienol, 5alpha-androst-16-en-3-one (5alpha-androstenone) was formed (32 +/- 1 ng/100 mg homogenate protein/h; mean +/- SEM, n = 3); surprisingly, no endogenous 5alpha-androstenone could be detected. No evidence was obtained for the production of testosterone or 5alpha-DHT from androstadienol. Using cytosolic fractions of human testis, specific (displaceable) binding of 5alpha-androstenone was determined, with binding sites of approximately 200 fmol/mg tissue and a Ka of approximately 8 nmol/l.

Auctions with Endogenous Quantity

This article studies auctions in which several sellers compete for the right to sell to a market characterized by a negatively sloped demand curve. In this environment the quantity traded becomes endogenous; this effect leads to three results concerning the outcomes of open versus (first-price) sealed-bid auctions. First, an open auction yields a higher expected price than does sealed bidding. Second, and more important, the open auction captures less of the potential gains from trade than does the sealed-bid auction. Third, for broad classes of demand curves, the efficiency gains from switching to sealed bids from an open auction accrue to both sellers and the buyer, so that all concerned parties would agree to the change. A direct application of the theory is to procurement, the heavy use of sealed bidding in procurement is seen as rational in light of these results. Auction models with endogenous quantity could be an alternative to price-setting oligopoly models for the study of price formation in general, for the latter impose strong information requirements on agents and yield only equilibrium price vectors, not equilibrium processes for determining prices.

THE DEVELOPMENT OF ELISA TO DETERMINE ABSCISIC ACID AND INDOLE-3-ACETIC ACID IN BULBOUS CROPS

A competitive ELISA was developed for the determination of the endogenous quantity of abscisic acid (ABA) and indole-3-acetic acid (IAA) in bulbous crops. Therefore, ABA and IAA were conjugated to bovine serum albumin by their carboxyl groups. Antibodies were raised in rabbits. With these antisera a good, reproducible, standard curve for ABA was developed. The standard curve for IAA, however, is less sensitive. It was not possible to determine IAA or ABA levels in crude plant extracts. To determine ABA levels in flower-buds of lily several purification steps were tried and will be presented, but the results are still rather variable.

M-Labeled Digraphs: An Aid to the Use of Structural and Simulation Models

M-labeled digraphs are defined and a technique for determination of the sign of sequences in such digraphs is presented. Conditions under which the sign of a sequence can be determined are derived. This work is motivated by the need to assess the structural effect of an “input” upon the endogenous quantities of an M-labeled digraph. A technique for comparing and combining the effects of structurally redundant inputs is presented. The theoretical development is followed by application to a prototypical Forrester model involving a population sector interactant with a housing sector.

Input and Output Redundancy

The (redundant) effect that an input might have upon an endogenous quantity reachable by it is characterized. The implication for an output is inferred by directional duality. Unsigned measures of redundancy are formulated and discussed. Then signed measures are developed by definition of the terms excitatory redundancy, inhibitory redundancy, and contradictory redundancy. The concept of an is presented as a visual means of displaying the structural effect of an input upon an endogenous quantity. The EI space also enables assessment of the degree of proximity between a pair of inputs in terms of the effect each has upon the same endogenous quantity and permits the aggregated effect of all inputs upon the quantity to be determined. These methods provide managerial insight into the behavioral nature of the causality inherent within a structural model.

Gibberellins and the photosensitivity of isolated embryos from non-stratified apple seeds

The phytochrome system is responsible for the photosensitivity of dormant, isolated apple embryos in culture. Maximum photosensitivity occurs on the second day of culture and it is unaffected by gibberellins (GAs) in concentrations below 10(-4)M. Higher concentrations of GA decrease the photosensitivity.The endogenous quantities of GA4 and GA7 were determined in embryos grown at white light, in darkness and in darkness following an exposure to red light. The GA7 level remained unaffected by the light conditions, whereas the amount of GA4 was three times higher in light or red-light-treated cultures than in the dark grown ones.Similar experiments were done using AMO-1618, an inhibitor of GA biosynthesis, which is also a strong inhibitor of apple seed germination. In this case the level of both GA4 and GA7 was light-independent. These experiments suggest that the phytochrome system participates in the regulation of GAs biosynthesis by mediating one of the last steps of GA4 formation.