107 research outputs found
Economic Policy Uncertainty and Firm-Level Investment
This paper examines the effect of economic policy uncertainty and its components on firm-level investment. It is found that economic policy uncertainty in interaction with firm-level uncertainty depresses firmsâ investment decisions. When firms are in doubt about costs of doing business due to possible changes in regulation, cost of health care and taxes, they become more guarded with investment plans. The effect of economic policy uncertainty on firm-level investment is greater for firms with higher firm-level uncertainty and during a recession. News-based policy shock has a significantly negative long-term effect on firmsâ investment. Federal expenditure forecast interquartile range shock has a significant negative effect in the short- and long-run. Policy uncertainty does not seem to influence the investment decisions of the very largest firms (about 20% of listed firms)
Economic Policy Uncertainty and Firm-Level Investment
This paper examines the effect of economic policy uncertainty and its components on firm-level investment. It is found that economic policy uncertainty in interaction with firm-level uncertainty depresses firmsâ investment decisions. When firms are in doubt about costs of doing business due to possible changes in regulation, cost of health care and taxes, they become more guarded with investment plans. The effect of economic policy uncertainty on firm-level investment is greater for firms with higher firm-level uncertainty and during a recession. News-based policy shock has a significantly negative long-term effect on firmsâ investment. Federal expenditure forecast interquartile range shock has a significant negative effect in the short- and long-run. Policy uncertainty does not seem to influence the investment decisions of the very largest firms (about 20% of listed firms)
Oil Price Shocks, Firm Uncertainty and Investment
It is found that an oil price shock in interaction with a firmâs stock price volatility has a ânegative effect on investment by that firm, both in the short and long-term. In the presence of âthis interaction term, linear variables in oil price shocks are not statistically significant. There is âevidence that for the short-term effects of the interaction variable, the particular magnitude of an âoil price shock may not be as important as the fact that there is an oil price shock. For the long-âterm effects, however, the magnitude of the oil price shock does matter. Over a longer horizon, âoil price shocks depress investment more at firms facing greater uncertainty. An increase in firm âstock price volatility continues to reduce the link between sales growth and investment in the âpresence of oil price shocks as in Bloom et al. (2007).
Domestication of Oryza species eco-evolutionarily shapes bacterial and fungal communities in rice seed
Abstract
Background
Plant-associated microbiomes, which are shaped by host and environmental factors, support their hosts by providing nutrients and attenuating abiotic and biotic stresses. Although host genetic factors involved in plant growth and immunity are known to shape compositions of microbial communities, the effects of host evolution on microbial communities are not well understood.
Results
We show evidence that both host speciation and domestication shape seed bacterial and fungal community structures. Genome types of rice contributed to compositional variations of both communities, showing a significant phylosymbiosis with microbial composition. Following the domestication, abundance inequality of bacterial and fungal communities also commonly increased. However, composition of bacterial community was relatively conserved, whereas fungal membership was dramatically changed. These domestication effects were further corroborated when analyzed by a random forest model. With these changes, hub taxa of inter-kingdom networks were also shifted from fungi to bacteria by domestication. Furthermore, maternal inheritance of microbiota was revealed as a major path of microbial transmission across generations.
Conclusions
Our findings show that evolutionary processes stochastically affect overall composition of microbial communities, whereas dramatic changes in environments during domestication contribute to assembly of microbiotas in deterministic ways in rice seed. This study further provides new insights on host evolution and microbiome, the starting point of the holobiome of plants, microbial communities, and surrounding environments.
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