Do you need to be a native English speaker to understand statistics?

A barbell phenomenon is when occurrences are heavier on both sides of a distribution with nothing in between.

Are there any people who are ranked by their income? In a barbell economy, you would see a whole bunch of people on the low income side of the graph and another whole bunch of people on the high income side, with scantly anyone in between. The barbell shape of the formula of the income frequency plot suggests the disappearance at the expense of the middle class.

Whereas a barbell investment is when the investor chooses to have a lot of investments of short-term returns as well as a lot of investments with long-term returns, without any spreading of investments across the mid-term range.

Statistics conventionally names statistical behaviours due to the similarity of shapes of the graphs/charts with physical items familiar to the lay public.

For example the bathtub curve, which is a timeline plot of the frequency of failures of a product The tub curve is a model for the whole product. Most products conform to the bathtub curve behaviour. Most items of a product would either fail early, or last a long time, with few failures in between. In order to be a good product, quality engineering requires a product to be in accelerated stress before being sold, so that the early-bird or infant failure would be caught and prevented from landing on customers’ hands. As a consequence, quality engineering requires a product to have accelerated stress before being sold, so that the early-bird or infant failure would be caught and prevented from landing on customers’ hands.

Addendum: Just a finer point of clarification – the barbell graph is not so much from the frequency plot but from the occurrence distribution plot. Why there is no negative frequency if the theory behind the data calls for charting imaginary frequencies if there

is no negative frequency if the theory behind the data calls for charting spectral frequencies.

William Frey used the term barbell economy in his lecture in 2002 to describe what’s happening to wealth in the US. As classes, the very rich and the very poor

are growing at either end of the spectrum, with an ever-dimining middle class between these extremes. As a long-time demographer dealing with class, he warns that for economic stability, we need a growing, not a shrinking middle class.

As a dictionary, the word job market has been used to describe industry polarities (increasingly polarizing into a low income job and high income jobs, with a loss of middle-income jobs), the retail market (where the high-end retailers perform well, the low-end retailers perform well, and the middle

market struggles) and other polarities.