The Notation for Panel Data Is $\left( X _ { i t } , Y _ { i t } \right) , i = 1 , \ldots , n \text { and } t = 1 , \ldots , T$

question 20

Multiple Choice

The notation for panel data is $\left( X _ { i t } , Y _ { i t } \right) , i = 1 , \ldots , n \text { and } t = 1 , \ldots , T$
because

• A) we take into account that the entities included in the panel change over time and are replaced by others.
• B) the X 's represent the observed effects and the Y the omitted fixed effects.
• C) there are n entities and T time periods.
• D) n has to be larger than T for the OLS estimator to exist.

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Definitions:

Erythema

Redness of the skin or mucous membranes, often caused by dilation and congestion of the capillaries, typically a sign of inflammation or infection.

Ecchymosis

The appearance of a large, discolored area on the skin, caused by bleeding underneath, typically resulting from bruising.

Skin Mobility

The ease with which skin can be moved or lifted, often assessed in the evaluation of edema, dehydration, or certain skin conditions.