1,721,119 research outputs found
Some Statistical Investigations on the Nature and Dynamics of Electricity Prices
No full textThis work analyzes the log-returns of daily electricity prices from the NordPool day-ahead market. We study both the unconditional growth rates distribution and the distribution of residual shocks obtained with a non-parametric filtering procedure based on the Cholesky factor algorithm. We show that, even if the Subbotin family of distributions is able to describe the empirical observations in both cases, the Subbotin fit obtained for the unconditional growth rates and for the residual shocks reveal significant differences. Indeed, the sequence of log-returns can be described as the outcome of an aggregation of Laplace-distributed shocks with time-dependent volatility. We find that the standard deviation of shocks scales as a power law of the initial price level, with scaling exponent around -1. Moreover, the analysis of the empirical density of shocks, conditional on the price level, shows a strong relationship of the Subbotin fit with the latter. We conclude that the unconditional growth rates distribution is the superposition of shocks distributions characterized by decreasing volatility and fat-tailedness with respect to the price level
Gibrat's Law and Diversification
No full textThis article presents an analysis of the growth patterns of the worldwide top 200 firms in the pharmaceutical industry. A test of the Gibrat's Law of Proportionate Effect is performed and we find, in line with previous literature, a violation concerning the variance of growth. Using disaggregated data on sub-markets, we are however able to show that this violation can be completely accounted for by a diversification effect, namely a scale relation between the number of sub-markets in which a firm is active and its size. To interpret these findings, we propose a stochastic branching model of firm diversification consistent with a notion of cumulative corporate competence
Why are distributions of firm growth rates tent-shaped?
No full textRecent empirical analyses on different datasets have revealed a common exponential behavior in the shape of the probability density of the corporate growth rates. We present new evidence on this topic from the Italian Manufacturing Industry and propose a very simple mechanism that, under rather general assumptions, provides a
robust explanation for the observed regularities
Financial fragility and the distribution of firm growth rates
No full textAnalyzing a comprehensive database of limited liability manufacturing firms this paper investigates the relation between a firm’s financial situation and its conditional expected growth rate. Specifically, using quantile regressions, we obtain a quantitative characterization of this relation for different quantiles of the growth rates distribution. We find that simple location-shift models, as for instance the OLS, provide a poor and potentially misleading representation of the growth-finance relation. Indeed, the vast majority of the explanatory variables considered are associated with modifications in the support of the growth rates distribution (scale-effect), even when the relation of the same variables with the expected growth is negligible. Moreover, we show that financial conditions impact differently on the growth dynamics of young and old firms. Finally, our investigations reveal that the results obtained with quantile regressions appear robust with respect to possible mispecifications of the empirical model
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