The estimation of the holding periods of financial products has to be done in a dynamic process in which the size of the observation time interval influences the result. Small intervals will produce smaller average holding periods than bigger ones. The approach developed in this paper offers the...

Cryptocurrencies such as Bitcoin rely on a proof-of-work system to validate transactions and prevent attacks or double-spending. A new proof-of-work is introduced which seems to be the first number theoretic proof-of-work unrelated to primes: it is based on a new metric associated to the Collatz...

We consider a linear panel event-study design in which unobserved confounds may be related both to the outcome and to the policy variable of interest. We provide sufficient conditions to identify the causal effect of the policy by exploiting covariates related to the policy only through the...

Let <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$$\{W_m\}{_{m\ge 1}}$$</EquationSource> </InlineEquation> be the sequence of weak records from a discrete parent random variable, <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$$X$$</EquationSource> </InlineEquation>, supported on the non-negative integers. We obtain a new characterization of geometric distributions based on an additive property of weak records: <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$$X$$</EquationSource> </InlineEquation> follows a geometric...</equationsource></inlineequation></equationsource></inlineequation></equationsource></inlineequation>

The model for prediction of drought magnitudes is based on the multiplicative relationship: drought magnitude (M)=drought intensity (I) × drought duration (L), where I, L, and M are presumed to obey respectively the truncated normal probability distribution function (pdf), the geometric pdf,...