Pencil it in
there is really no need to have a reason to shop, but the calendar does come with a few built-in. cutting out the gift-giving incentives (birthdays, anniversaries, holidays) and the "shop now!" black friday imperative, and looking just at the impetus for personal-shopping, my primary cause for the shopping effect is the change in season. i used to reassess my needs and supplies when the weather still shifted with some degree of predictability, but with fall clothes being shown and shared via fashion runways in the spring, and spring collections revealed in the fall, it is possible that the industry preemptively jump starts the process in me, and gets the ball rolling. anyway, when i was younger, the seasons delivered an excuse to shop. i grew up without real seasons yet the magazines always got me drooling for corduroys in september for 'back-to-school' (those same corduroys got me panting in 90 degree heat, but that's another story).
as the beginnings of semesters and beginnings of vacations stopped defining my year, i found myself living across the country among the long-dreamed of seasons. real, actual, perceptible changes in weather. hot, cold, the works. the works are getting noticeably more and more gummed up, i'll admit. this year, summer lasted a long time, then it was suddenly winter, then it was fall for a week, then back to winter, then a day of spring and now it's winter again. but for me, september still means fall (blazers, cardigans), even if it's 80 degrees outside, and december is winter (hats, boots). spring (dresses) will roll around in april, even if it's snowing, and summer (sandals) comes in june. i'm programmed, i think, to make sure i have the necessary supplies, and if not, it's my job to shop for them.
if there were absolutely no seasons, and therefore no need for seasonal wardrobes (even if you live in a mild climate, the media heralds in the new season and delivers a sense of cycle), how would your shopping habits be effected?