The determinants of changes in the organization of production: Evidence from Spanish plant-level data

In this paper we empirically examine the determinants of changes in the organization of production using detailed information on a data set from a new plant-level survey of 1003 plants covering the full range of manufacturing industries in Spain. In particular, and among many other things, survey respondents were asked how service outsourcing practices had changed in the last three years. The answer to this question is indicative of the changes in the importance of backward integration for each of the plants studied. Using other information provided in the survey, we relate the reported changes in outsourcing to changes in other relevant dimensions as possible determinants of the boundaries of the firm. These dimensions are: plant size, downstream market power, cost of inputs, price and quality of the final good and technological progress. Our findings show that outsourcing increases are strongly positively correlated with increases in market share and in market competition. We also find that outsourcing increases when plants face simultaneous increases in product quality and product prices and that it decreases when plants face simultaneous increases in market share and market competition. Finally, we find that multi-plant and one-plant firms adjust their outsourcing practices differently to outside changes. Since neither TCE nor PRT theories of vertical integration fully explain the patterns found in our data, we close this paper by following Adam Smith's claim that the extent of the market seems to be the only factor consistently limiting the degree of specialization in our setting.outsourcing; vertical integration; competition; manufacturing plants;

Is Seniority-Based Pay Used as a Motivation Device? Evidence from Plant Level Data

In this paper we use data from industrial plants to investigate if seniority-based pay is used asa motivational device for production workers. Alternatively, seniority-based pay could simplybe a wage setting rule not necessarily related to the provision of incentives. Unlike previouspapers, we use a direct measure of seniority-based pay as well as measures of monitoringdevices and piece-rates. We find that firms that offer seniority-based pay are less likely tooffer explicit incentives. They are also less likely to invest in monitoring devices. We alsofind that firms that offer seniority-based pay are more likely to engage in other humanresource management policies that result in long employment relationships. Overall theseresults suggest that seniority-based pay is indeed used as a motivation device.Human resource management practices, incentives, monitoring

Time-dependent toxicity of neonicotinoids and other toxicants: Implications for a new approach to risk assessment

A fundamental goal of toxicology is to determine safe levels of exposure to potentially poisonous substances for humans and the environment. Traditionally, safe levels of a chemical have been derived from the non-observable effect level (NOEL) estimated in laboratory toxicity bioassays with organisms which are representative of certain taxa. There are fundamental problems with the validity of this approach, both conceptual and statistical in nature. Firstly, the outdated NOEL concept is being replaced by the no-effect concentration (NEC) level, which assumes that toxic chemicals do not have any effect on a population of organisms at very low concentrations. Recent developments in ecotoxicology, however, suggest that some toxicants can produce effects at any concentration level provided their exposure time is sufficiently long. Consequently, risk assessment of these chemicals, which includes neonicotinoid insecticides, some carcinogenic substances and certain metallic compounds, may require entirely new approaches. Secondly, the traditional approach to toxicity testing is to consider dose or concentration-effect relationships at arbitrarily fixed exposure durations which are supposed to reflect âacuteâ or âchronicâ time scales. This approach measures the proportion of all exposed individuals responding by the end of those fixed exposure times. However, the endpoint values obtained this way cannot be linked to make predictions for the wide range of exposures encountered by humans or in the environment, thus leading to serious underestimates of actual risk. In order to overcome this handicap, an increasing number of researchers are using a variant of the traditional toxicity testing protocol which includes time to event (TTE) methods. This TTE approach measures the times to respond for all individuals, and provides information on the acquired doses as well as the exposure times needed for a toxic compound to produce any level of effect on the organisms tested. Consequently, extrapolations and predictions of toxic effects for any combination of concentration and time are now made possible. Examples are shown to demonstrate that this approach is superior to current toxicological testing procedures, and has important implications for risk assessment of chemicals, particularly when the chemical has delayed toxic effects in a time-dependent manner

Impacts of Pesticides on Honey Bees

This chapter focuses on the detrimental effects that pesticides have on managed honey bee colonies and their productivity. We examine first the routes of exposure of bees to agrochemicals used for crop protection and their application to crops, fate and contamination of water and plants around the fields. Most of the time, the exposure of bees to pesticides is through ingestion of residues found in the pollen and nectar of plants and in water. Honey bees are also exposed to pesticides used for the treatment of Varroa and other parasites. The basic concepts about the toxicity of the different kinds of pesticides are explained next. Various degrees of toxicity are found among agrochemicals, and emphasis is given to the classic tenet of toxicology, “the dose makes the poison,” and its modern version “the dose and the time of exposure makes the poison.” These two factors, dose and time, help us understand the severity of the impacts that pesticides may have on bees and their risk, which are analysed in the third section. Sublethal effects are also considered. The final section is devoted to some practical advice for avoiding adverse impacts of pesticides in beekeeping

Crucial aspects of the initial mass function (I): The statistical correlation between the total mass of an ensemble of stars and its most massive star

Our understanding of stellar systems depends on the adopted interpretation of the IMF, phi(m). Unfortunately, there is not a common interpretation of the IMF, which leads to different methodologies and diverging analysis of observational data.We study the correlation between the most massive star that a cluster would host, mmax, and its total mass into stars, M, as an example where different views of the IMF lead to different results. We assume that the IMF is a probability distribution function and analyze the mmax-M correlation within this context. We also examine the meaning of the equation used to derive a theoretical M-char_mmax relationship, N x int[Char_mmax-mup] phi(m) dm = 1 with N the total number of stars in the system, according to different interpretations of the IMF. We find that only a probabilistic interpretation of the IMF, where stellar masses are identically independent distributed random variables, provides a self-consistent result. Neither M nor N, can be used as IMF scaling factors. In addition, Char_mmax is a characteristic maximum stellar mass in the cluster, but not the actual maximum stellar mass. A -Char_mmax correlation is a natural result of a probabilistic interpretation of the IMF; however, the distribution of observational data in the N (or M)-cmmax plane includes a dependence on the distribution of the total number of stars, N (and M), in the system, Phi(N), which is not usually taken into consideration. We conclude that a random sampling IMF is not in contradiction to a possible mmax-M physical law. However, such a law cannot be obtained from IMF algebraic manipulation or included analytically in the IMF functional form. The possible physical information that would be obtained from the N (or M)-mmax correlation is closely linked with the Phi(M) and Phi(N) distributions; hence it depends on the star formation process and the assumed.Comment: Accepted by A&A; 16 pages, 10 figure

Crucial aspects of the initial mass function (II): The inference of total quantities from partial information on a cluster

In a probabilistic framework of the interpretation of the initial mass function (IMF), the IMF cannot be arbitrarily normalized to the total mass, M, or number of stars, N, of the system. Hence, the inference of M and N when partial information about the studied system is available must be revised. (i.e., the contribution to the total quantity cannot be obtained by simple algebraic manipulations of the IMF). We study how to include constraints in the IMF to make inferences about different quantities characterizing stellar systems. It is expected that including any particular piece of information about a system would constrain the range of possible solutions. However, different pieces of information might be irrelevant depending on the quantity to be inferred. In this work we want to characterize the relevance of the priors in the possible inferences. Assuming that the IMF is a probability distribution function, we derive the sampling distributions of M and N of the system constrained to different types of information available. We show that the value of M that would be inferred must be described as a probability distribution Phi[M; m_a, N_a, Phi(N)] that depends on the completeness limit of the data, m_a, the number of stars observed down to this limit, N_a, and the prior hypothesis made on the distribution of the total number of stars in clusters, Phi(N).Comment: Accepted by A&A; 9 page

Ornamental plants on sale to the public are a significant source of pesticide residues with implications for the health of pollinating insects

Garden centres frequently market nectar- and pollen-rich ornamental plants as “pollinator-friendly”, however these plants are often treated with pesticides during their production. There is little information on the nature of pesticide residues present at the point of purchase and whether these plants may actually pose a threat to, rather than benefit, the health of pollinating insects. Using mass spectrometry analyses, this study screened leaves from 29 different ‘bee-friendly’ plants for 8 insecticides and 16 fungicides commonly used in ornamental production. Only two plants (a Narcissus and a Salvia variety) did not contain any pesticide and 23 plants contained more than one pesticide, with some species containing mixtures of 7 (Ageratum houstonianum) and 10 (Erica carnea) different agrochemicals. Neonicotinoid insecticides were detected in more than 70% of the analysed plants, and chlorpyrifos and pyrethroid insecticides were found in 10% and 7% of plants respectively. Boscalid, spiroxamine and DMI-fungicides were detected in 40% of plants. Pollen samples collected from 18 different plants contained a total of 13 different pesticides. Systemic compounds were detected in pollen samples at similar concentrations to those in leaves. However, some contact (chlorpyrifos) and localised penetrant pesticides (iprodione, pyroclastrobin and prochloraz) were also detected in pollen, likely arising from direct contamination during spraying. The neonicotinoids thiamethoxam, clothianidin and imidacloprid and the organophosphate chlorpyrifos were present in pollen at concentrations between 6.9 and 81 ng/g and at levels that overlap with those known to cause harm to bees. The net effect on pollinators of buying plants that are a rich source of forage for them but simultaneously risk exposing them to a cocktail of pesticides is not clear. Gardeners who wish to gain the benefits without the risks should seek uncontaminated plants by growing their own from seed, plant-swapping or by buying plants from an organic nursery

Rapid rise in toxic load for bees revealed by analysis of pesticide use in Great Britain

A strong argument can be made that the European Union has the most rigorous regulatory system for pesticides in the world, and that modern pesticide use poses fewer environmental threats than older regimes. Nevertheless, the impacts of pesticides on bees and other non-target organisms are much debated in Europe as elsewhere. Here we document changing patterns of pesticide use in arable and horticultural crops in Great Britain from 1990 to 2015. The weight of pesticides used has approximately halved over this period, but in contrast the number of applications per field nearly doubled. The total potential kill of honeybees (the total number of LD50 doses applied to the 4.6 million hectares of arable farmland in Great Britain each year) increased six-fold to approximately 3 1016 bees, the result of the increasing use of neonicotinoids from 1994 onwards which more than offset the effect of declining organophosphate use. It is important to stress that this does not mean that this number of bees will be killed, and also to acknowledge that our simple analysis does not take into account many factors such as differences in persistence, and timing and mode of application of pesticides, which will affect actual exposure of non-target organisms. Nonetheless, all else being equal, these data suggest that the risk posed by pesticides to non-target insects such as bees, other pollinators and natural enemies of pests, has increased considerably in the last 26 years