Statistical Power

What is power?  Merriam Webster defines power as the “possession of control, authority, or influence over others.”  The power I will talk about today, however, is statistical power.  Statistical power measures the ability of a statistical test to determine whether the null hypothesis is false.  For instance, in the U.S. judicial system, the null hypothesis…

Homegrown Terror

On 60 Minutes this week, I saw a piece called “Uncovering the Roots of Homegrown Terrorism” which documents the rise in the number of American citizens who are receiving training in Pakistan for Terrorists operations.  Many of these ‘homegrown terrorists’ are ethnically Pakistani, though certainly not all.  The story also documents a similar problem with…

Health Spending Climbs to 16.2% of GDP

From the CMS Office of the Actuary: U.S. health care spending growth decelerated in 2008, increasing 4.4 percent compared to 6.0 percent in 2007, as spending growth slowed for nearly all health care goods and services, particularly for hospitals. Health spending growth for state and local and private sources of funds also slowed while federal…

The History of Least Squares

Let us say you have 10 observations of 2 different variables.  How do you determine which of the observations to use?  Should you throw out the outliers?  Should you only include the most similar values?  Does more observations increase or decrease the amount of measurement error? These problems can be answered by the discipline of Statistics.…

Health Care Spending

The California HealthCare Foundation has a great document summarizing many useful Health Care Cost Statistics (see full text or fact sheet).  Some of the highlights: Health Care spending as a percentage of GDP is projected to grow 16.0% of GDP in 2006 to 19.5% of GDP in 2017. Average health care spending per capita was…