I operate a small ice-cream stand on campus called Ice-Campusades. I order the same number and same variety of ice-creams from the supplier every day, however, the demand for my ice-creams varies on a day-to-day basis. There are several factors that may explain why the demand of my ice-creams is not uniform even though the supply remains uniform every day. One of the reasons may be the student population on campus. On some daysd, more students have classes on campus and as a result, I enjoy higher demand for my ice-creams. On other days, the demand for my ice-creams is low because fewer students have classes on those particular days. This may explain why Fridays are slow in terms of demand for my ice-creams because the campus is relatively empty on Fridays.

The variations in demand for my ice-creams can also be explained by the changing preferences and lifestyles of the students. Sometimes the weather is more suitable for ice-cream treats such as a sunny day. Similarly, the social events on campus such as the music concerts also give a boost to the demand for my ice-creams. When the weather is relatively cool, a cold treat like ice-cream may not have much appeal, even for loyal ice-cream fans.

There are many substitute products for ice-cream sold on campus including donuts, pastries, and cakes. I keep my prices same but the vendors of other products run sales promotions from time-to-time. During promotions, the substitute products enjoy higher demand at the expense of my ice-creams because they seem like better values than my ice-creams to many students. Similarly, there are complementary products, too. Ice-cream makes a good sweet treat after a regular meal or a spicy snack food item like burgers and fried chicken.

The income levels of the students may also partially explain why the demand for my icrecreams varies on a day-to-day basis. Many students work part-time and are usually paid on a bi-weekly basis. Some do freelance work and earn on a daily basis. When students have just received a paycheck or they may have extra money on a given day, they are more likely to splurge on a treat like ice-cream.

A month later, the school allows a competing student to sell ice-cream on campus. The price of ice-cream will fall on campus because the supply of ice-cream will increase. I was the only seller for a month but now there will be two sellers. The supply curve will move to the right while the demand curve will stay same.

The demand for my ice-creams varies on a day-to-day basis for one or more of several reasons. One reason is the size of student population on campus that varies on a daily basis, depending upon the number of class sessions among other things. The preferences and lifestyles of the student also affect the demand for my ice-cream. Sometimes the weather is more suited to ice-cream treat. Similarly, certain campus events may also increase the temptation for ice cream. The demand for my ice-creams is also affected by the number of substitute and complementary products on campus. Sometimes the students simply choose substitute products in place of ice-cream and sometimes the sales promotions make substitute products better value than the ice-cream. Similarly, the sale of complementary products sometimes boosts the demand for my ice-creams as well. The income levels and disposable income of students also affect the demand for my ice-creams. I was the only seller of ice-cream for a month but another student will be allowed to sell ice-cream which should reduce the price of ice-cream on campus due to an increase in supply of ice-cream.