Because Life Happens...

Marriage

Birth

Divorce

Promotion

Transfer

Deployment

Death

Bankruptcy

Medical Issues

Neighbors suck

Neighborhood changes

Lottery Winner

Inheritance

and...

and...

and...

• Size
• School zones are huge factors in my market.
• Lifestyle changes necessitating different type of house.
• Physical challenges - 2-story needs to be a ranch.
• Familial changes
• Divorce
• Only had neighborhood changes for reasons like improved amenities.
• Job change/promotion/transfer
• Death (trust or probate sale)
• Need to incorporate two homes into one multi-family living arrangement

And, the list goes on, I'm sure! These are just off of the top of my head from recent sales.

Dario Ferreira has the ones I thought of.  In addition to his, moving for or because of a job comes to mind, as does divorce or death of a family member (or member of extended family), moving to care for elderly family or those left by the death of a family member.

The list goes on and on and on and on ... 

as does the beat ... the beat goes on. 

You've got some great lists here including those from Debe Maxwell, CRS and Thomas J. Nelson.  

Minot Air Force base accounted for half of my business... always coming and always going. Aside from that many sellers were retiring to the Southern States.

Trade-up or trade-out

I think you named the top 3 here are some more, school districts, not enough natural light, not facing the right direction, neighbors, finaces, zoning laws.

Getting older
Weather
Neighborhood change
Death of spouse
Financial situation
Schools
Won the lottery :)

Job change... baby on the way... kids have moved out "empty nest"... looking for a new project... need something to blog about...

Changes:    Job.    Household Size.   

There's a start.  

Maybe it's time to start some internal brainstorming.   

Life situations such as health, death, job relocation, job loss, won the lottery, inherited $$, becoming a multi-generational household, military etc

I've always practiced with the idea 'where you are going is more important than where you have been.'

They move because the see a place they want that suits them better. Of course that could mean moving to Madison where there work will be.

A motivated seller sees a place they want.

In my second home market there is 7 year itch that dominates. After that it is the 3ds. Death, disease and divorce

Weather, job, retirement, age, marriage, divorce, kids, traffic, death of family member, assited living needed in near future, convenience to hospital, annoying HOA's, annoying neighbors, job transfer, get closer to grandkids, needs one level living, reduce or eliminate yard work, pets, access to public transportation needed, etc

Lots of great answers and I feel like the most common reasons have been covered. If you want to create a reason, one could add using the cycle of the real estate market and one's primary residence to create wealth - downsize in an up market, upsize in a down market. Note the "up" and "down" don't have to be the physcal size of the property - more like upgrade in down market  - sell the expensive home when prices are up and by a cheaper home. When the next down cycle comes along - sell the cheaper home and upgrade. When the market shifts to the next up cycle - ride it up for awhile - sell and repeat.

Just time to move on and we are in a position to do it!

Loss of job, divorce, relocating for work, can not go up and down stairs any more. Then having a baby, getting married to a girl with 3 kids who will also be moving in. Here is a few more...

in my market there are two main reasons... older people moving "closer to kids and doctors" and weekend/vacation people "life got so busy we never come" sellers.  

An upcoming assessment!

Taxes got too high; knees too weak to tackle the stairs; move closer to kids; tired of shoveling snow and so on...

With so many job losses, many are unable to pay their mortgage payments. We will see more multi-generation occupants in homes.

Kids settled need to move to other area they want to live close to nature. 

There are many reasons for sellers to want to sell. For some older couples, empty nestors, once all the kids have gone off to college or moved out, their current home may be too large. So, yes, downsize is one motivating reason. Another reason expanding families may need more space. Or, for those who may be facing an unfortunate situation such as a job loss, divorce, etc, may want to or are forced to sell their homes.