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41.
In this paper, we predict that venture capital (VC) backed initial public offerings (IPOs) will attract more attention than non-VC-backed IPOs, as VCs offer important signals to investors searching for information about entrepreneurial firms. We use a measure developed by Google (i.e., Trends) to capture the spikes in investors' attention experienced by firms in the time period surrounding their IPOs. Our results demonstrate that firms backed by VCs enjoy a far greater spike in attention than their counterparts. Furthermore, we find that firms with more prominent VCs, a larger number of VCs, and VCs situated at farther geographic distances exhibit significantly greater spikes in investors’ attention during the week of their IPO. Combined, the findings show a clear demarcation between entrepreneurial firms with or without VC backing, they bring to the fore new upshots stemming from the relationship between VCs and entrepreneurial firms, and they raise new potential questions on this relationship and beyond.  相似文献   
42.
Research on families in the middle and later years came into its own during the 1990s, documenting the complexity, malleability, and variety of older family connections. We examined 908 articles on family gerontology topics, observing 4 trends: Conceptually, an appreciation for pluralism and resilience as individuals and families age is apparent. Theoretically, life course, feminist, socioemotional selectivity, and family solidarity theories are increasingly applied to intergenerational family relations. Methodologically, new interest in qualitative methods for studying diverse groups has improved the depth with which aging studies can account for variability in old age; new quantitative methodologies have allowed greater sophistication in dealing with longitudinal data. Substantively, there is greater understanding of family caregiving, social support, parent‐child relationships, marital transitions, and grandparenting relationships. The field is poised to take even greater risks in fulfilling the promise of studying linked lives over time.  相似文献   
43.
In this paper, we discuss some theoretical results and properties of the discrete Weibull distribution, which was introduced by Nakagawa and Osaki [The discrete Weibull distribution. IEEE Trans Reliab. 1975;24:300–301]. We study the monotonicity of the probability mass, survival and hazard functions. Moreover, reliability, moments, p-quantiles, entropies and order statistics are also studied. We consider likelihood-based methods to estimate the model parameters based on complete and censored samples, and to derive confidence intervals. We also consider two additional methods to estimate the model parameters. The uniqueness of the maximum likelihood estimate of one of the parameters that index the discrete Weibull model is discussed. Numerical evaluation of the considered model is performed by Monte Carlo simulations. For illustrative purposes, two real data sets are analyzed.  相似文献   
44.
This paper develops a novel and efficient algorithm for Bayesian inference in inverse Gamma stochastic volatility models. It is shown that by conditioning on auxiliary variables, it is possible to sample all the volatilities jointly directly from their posterior conditional density, using simple and easy to draw from distributions. Furthermore, this paper develops a generalized inverse gamma process with more flexible tails in the distribution of volatilities, which still allows for simple and efficient calculations. Using several macroeconomic and financial datasets, it is shown that the inverse gamma and generalized inverse gamma processes can greatly outperform the commonly used log normal volatility processes with Student’s t errors or jumps in the mean equation.  相似文献   
45.
Researchers consider older women in rural Appalachia to have low levels of agency and high levels of fatalism regarding decision making about cancer treatment. Using the life course perspective, we examined older women’s agency with information seeking about gynecological cancer. Semistructured interviews with 20 White women living in central Appalachia revealed four trajectories: Surrendering Control, Accepting Death, Self-Care, and Advocacy, each with its own forms of agency. Some women experienced personal transformation, increased self-efficacy, and a passion for community empowerment. Fatalism was not understood apart from placing trust in medical expertise. We implore researchers to further explore rural expressions of agency.  相似文献   
46.
Drawing on the complementary assets framework, this study explores the moderating effect of innovation‐focused complementary assets (CA‐I) on the relationship between a data‐driven supply chain orientation (DDSCO) and firm financial performance. To test the moderating effect, survey data gathered from 329 manufacturing firms in China were analysed using a moderated regression analysis. The results indicate that DDSCO has a significant positive effect on financial performance, and that capabilities for product and process innovation function as complementary assets moderating the DDSCO–performance relationship. The findings suggest that innovation‐focused complementary assets are performance differentiators when paired with a DDSCO and explain why some firms obtain financial benefits from the development of a DDSCO while others do not. Specifically, competitive advantage from a DDSCO may not be realized unless CA‐I and potentially other complementary assets are harnessed, thus providing useful practical guidance to managers. Hence, the study provides empirical support for the complementary assets framework.  相似文献   
47.
Urban green spaces have been recognized as an important source of ecosystem services, whose quantification requires the determination of quantities related to energy, water, carbon and soil nutrient content. In this paper we propose a stochastic ecohydrological model that couples two existing models for water and nutrients in urban soil at the single street-tree scale. The model input are rainfall and irrigation, for water, and deposition and fertilization, for nitrogen, while the output are evapotranspiration, runoff and deep percolation, for water, and plant uptake and leaching, for nitrogen. The various terms are related to the amount of paved and impervious surfaces that surround the tree trunk and regulate the water and nutrient fluxes in and out the soil. Particular attention is paid to the effects of seasonal variations on plant water and nutrients through a temporal variation of the hydrologic variables (i.e., temperature and rainfall intensity and frequencies). The average model outputs are preliminarily compared with the scant existing literature data, supporting the model application to cities with different climatic conditions. The model results are used to estimate the potential for ecosystem services like tree cooling effects, soil carbon sequestration or storm-water management. Because of the minimal structure of the proposed model, it requires a very low amount of data, while accounting for the stochastic input of rainfall. In the context of climate change and increasing urbanization, the model may offer useful indications to urban planners to enhance ecosystem services while minimizing irrigation, fertilization and their related costs.  相似文献   
48.
The aim of this paper is to empirically study the effect of uncertainty on private consumption using a sample of Spanish households, and therefore, to test the existence of a precautionary motive for saving. Using data provided by the Spanish Survey of Household Finances and the Labour Force Survey we construct several uncertainty measures that are commonly used in the literature and an additional indicator based on job insecurity data, and we consequently estimate different econometric models under the life-cycle/permanent income hypothesis, including these measures of uncertainty. Our results are twofold: first, we find evidence in favour of the precautionary saving hypothesis. Secondly, we find that, unlike other variables related to the performance of the labour market (such as the unemployment rate) the job insecurity indicator is an appropriate variable to approximate income uncertainty in any macroeconomic context.  相似文献   
49.
A grounded theory qualitative study was developed to explore how grandparents perceive their role as socializing agents. Forty‐two grandparents with grandchildren aged from 6 to 12 years old participated in this study. Data were collected through focus groups, which were conducted until reaching data saturation and analyzed using the constant comparative method. Four general conclusions emerged from the study: (i) grandparents recognized the importance of getting involved in the socialization of grandchildren as supporters of parents' socializing role, and the need to adapt to social changes; (ii) they emphasized traditional value that were perceived in decline, and combination of warmth and involvement were considered the best way to help grandchildren internalize values; (iii) interaction with grandchildren helped grandparents to feel active and useful, increased their life purpose and gave them a second chance to enjoy what they could not with their own children; and (iv) grandparents also accused burden and role ambiguity. These results show the importance of developing family policies that recognize grandparents' socializing role. Also, interventions that promote strategies that enable grandparents to perform their role more successfully and to cope with possible family conflicts should be developed.  相似文献   
50.
Orthogonal fractional factorial designs and in particular orthogonal arrays (OAs) are frequently used in many fields of application, including medicine, engineering, and agriculture. In this article, we present a methodology and an algorithm to find an OA, of given size and strength, which satisfies the generalized minimum aberration criterion. The methodology is based on the joint use of polynomial counting functions, complex coding of levels, and algorithms for quadratic optimization and puts no restriction on the number of levels of each factor.  相似文献   
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