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As the year draws to a close, we look back on the most talked about Teacher Trendlines from 2014. We covered everything from teacher salaries to leave policies and in this edition, we highlight some of the most popular Teacher Trendlines from the past year.

Highs and lows in teacher salaries

Just as it was in 2013, our most popular Teacher Trendline in 2014 covered teacher salaries, highlighting those districts with the lowest and highest salaries for teachers with a BA and MA. But this year's teacher salary coverage had a twist— we looked at the purchasing power of teacher salaries in the context of housing affordability.

To do this, we created a "Teaching Housing Affordability Index" which we devised by dividing a teacher's annual salary by the median home value in the district (based on American Community Survey median housing values from 2008 to 2012). Albeit a blunt instrument for estimating housing affordability, the analysis was able to give good context to our comparison of raw teacher annual salaries. (If you're interested in teacher salaries, be sure to read our recent report Smart Money: What teachers make, how long it takes and what it buys them.)

Declines in student enrollment

June's Teacher Trendline about student enrollment trends in the nation's largest districts from 2009 to 2011 proved to be another popular post. In it, we looked at the largest enrollment changes in absolute and relative numbers. We found that while New York City experienced the largest decline in raw student enrollment numbers during this two-year period, Detroit experienced the biggest relative loss in students.

We dug a little deeper into what could have possibly caused these declines in the five districts with the biggest enrollment losses (Detroit, Philadelphia, Cleveland, New York City and Los Angeles). While there are several reasons that could explain these enrollment losses, we found that for some districts (Cleveland, New York City and Los Angeles) this could partially be explained by the decrease in the school-age population of each city.

We took a look at one other potential contributing factor for declines in student enrollment: charter schools. Contrary to what some may think, charter school enrollments in each of these cities, particularly in Los Angeles, did not seem to be the primary culprit behind declining student enrollment.

Trends in teacher leave policies

The most recent Teacher Trendline in October analyzed teacher leave policies across the country. We found that in the largest districts across the country, the average amount of general leave offered to teachers is 13.5 days, with most districts offering between 10 and 12 days for sick leave and one to three days for personal leave.

We covered a lot more in 2014; check out the list below to read any of the 2014 Teacher Trendlines in their entirety:

·  March: Teacher salaries and housing affordability

·  April: Teacher excessing and placement

·  June: Student enrollment

·  July: Teacher tenure

·  August: Student and teacher school year

·  September: Substitute teachers

·  October: Teacher leave

One of our New Year's resolutions for 2015 is to put out even more content in our Teacher Trendline— help us fulfill our goal by letting us know what district-level trends you want to read more about in 2015! Email your ideas to teachertrendline@nctq.org.