Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Thomas J. Brock is a CFA and CPA with more ...

True experiments, unlike anecdotal evidence, often require random sampling and random assignment. In this post, I try to explain the importance of random sampling; in my next post, I will explore ...

This paper presents the results of a limited investigation which brings into focus the difficulties encountered in developing exact distribution-free methods for stratified simple random sampling. It ...

In a recently published news story, we learn about a young doctor, Jake Deutsch, and his personal experience with coronavirus disease 2019. Deutsch tested positive for Covid-19 and checked himself ...