>However, a teacher for example, is given their summer pay as a lump sum at the end of the year instead of being distributed through their working hours. In practice this means that teachers who leave before the school year's end lose 25% of their yearly pay. This would be similar to if you quit your job, 25% of your pay was held as a punishment. No private employer would get away with this.

​

Umm... not even close. The pay you get is for 185 work days. If you leave during the year, you will be paid for the number of days you worked. If the amount you were paid doesn't cover all of the days you worked, the difference will be added to your last check.

The "summer pay" you speak of is the district paying out the balance owed on your contract if you decided (or the district required) your pay to be split into 26 checks instead of 21. The only reason why it's doled out in a balloon payment is because the year-to-year contracts expire on June 30 (before the start of the next fiscal year on July 1), so they can't have any remaining obligations on their books.