论文标题
非对称拉普拉斯秤的混合物,用于分布加密货币回报
Asymmetric Laplace scale mixtures for the distribution of cryptocurrency returns
论文作者
论文摘要
关于加密货币回报的最新研究表明,其分布可以高度峰,偏斜和重尾,并具有大量过量的峰度。为了适应所有这些特殊性,我们提出了不对称的拉普拉斯秤混合物(ALSM)分布家族。家庭的每个成员都是通过将条件不对称拉普拉斯(Al)分布的比例参数除以方便的混合随机变量的尺度参数,在正真实线的全部或部分中取值,并且其分布取决于参数vector $ \boldsymbolθ$,从而为所得的alsm提供了更大的灵活性。在AL分布方面,我们的家族成员允许偏斜和峰度的更大范围。出于说明目的,我们考虑了不同的混合分布。它们产生具有闭合形式概率密度函数的ALSM,其中在$ \boldsymbolθ$的方便选择下以特殊情况获得了Al分布。我们检查了我们的ALSM的某些特性,例如层次和随机表示以及实际关注的时刻。我们描述了一种EM算法,以获得所有考虑的ALSM的参数的最大似然估计。我们将这些模型符合两个加密货币的回报,考虑到几个经典分布进行比较。该分析表明,根据AIC,BIC和似然比测试,我们的模型如何代表所考虑的竞争对手的有效替代方案。
Recent studies about cryptocurrency returns show that its distribution can be highly-peaked, skewed, and heavy-tailed, with a large excess kurtosis. To accommodate all these peculiarities, we propose the asymmetric Laplace scale mixture (ALSM) family of distributions. Each member of the family is obtained by dividing the scale parameter of the conditional asymmetric Laplace (AL) distribution by a convenient mixing random variable taking values on all or part of the positive real line and whose distribution depends on a parameter vector $\boldsymbolθ$ providing greater flexibility to the resulting ALSM. Advantageously with respect to the AL distribution, the members of our family allow for a wider range of values for skewness and kurtosis. For illustrative purposes, we consider different mixing distributions; they give rise to ALSMs having a closed-form probability density function where the AL distribution is obtained as a special case under a convenient choice of $\boldsymbolθ$. We examine some properties of our ALSMs such as hierarchical and stochastic representations and moments of practical interest. We describe an EM algorithm to obtain maximum likelihood estimates of the parameters for all the considered ALSMs. We fit these models to the returns of two cryptocurrencies, considering several classical distributions for comparison. The analysis shows how our models represent a valid alternative to the considered competitors in terms of AIC, BIC, and likelihood-ratio tests.