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Question
Define secular trend
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Solution
It is a general tendency of time series to increase or decrease or stagnates during a long period of time, an upward tendency is usually observed in population of a country, production, sales, prices in industries, income or individuals etc.
A downward tendency is observed in deaths, epidemics, prices of electronic gadgets, water sources, mortality rate etc.
It is not necessarily that the increase or decrease should be in the same direction throughout the given period of time.
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