Trickle Up Theory: Trickle up theory also known as the bubble up theory is an innovative fashion theory born in the late 70s , and is believed to be the trend born among masses and flow from lower economic classes to affluent sections. Jeans are an omnipresent example of trickle up fashion trend – initially worn by miners, factory workers, and farmers, which gradually gained acceptance among larger audience and by 1970s jeans trickled up to become popular casual wear in America. T-shirt is another trickle-up style which was originally confined to blue-collar workers but evolved into must-have wardrobe staple due to its practicality and comfort. Born in the 1970s, the hippie style shifted from being just worn by the lower and middle-class alternative youth to a widespread trend. From 2012 it had a huge comeback with looks made of flow-y-tops and skirts paired with knit shrugs. An example is Ralph Lauren's spring collection (2011), which presented skirts with higher waist with the flow-y details towards the bottom.
Trickle Down Theory: The trickle-down effect can be seen as an antithesis to the trickle-up effect. Although the theory itself has only appeared since the 1950s under the title trickle-down effect, the concept can be traced back to Georg Simmel and Thorstein Veblen. The trend becomes affordable to general masses when its novelty wears out and the price falls gradually – by which time, the elite sections switch to new fashion trends – which again trickle down to masses with time, thereby enabling a continuous fashion cycle that flows from elite sections to lower economic classes.