WASHINGTON, DC—The math behind home ownership is a simple one for many: is it financially smarter to rent or buy in your particular area? Granted, in recent years, many people have chosen to rent for reasons that have nothing to do with money, but for the moment we'll set those aside.

The Most Stable Housing Market in the US

In the DC area there has been one immutable fact that helps tip the scale towards homeowner ship. The area is the most stable housing market in the nation. That is according to Freddie Mac's Multi-Indicator Market Index, or MiMi. The GSE just released it again on Wednesday with Washington DC ranked at 101. The other top stable markets rounding out the top five are North Dakota (96.5), Hawaii (95.9), Montana (95.7) and Utah (93.3). In general, the nation's housing market is improving, according to the report. Compared to the same time last year, 21 states and the District of Columbia had MiMi values in a stable range. Today it is 33.

To put the score in perspective, the national MiMi value stands at 82.5, indicating a housing market that is on its outer range of stable housing activity. It posted an improvement of +0.82 percent from October to November and a three-month improvement of +2.09 percent.

On a year-over-year basis, the national MiMi value has improved +7.23 percent. Since its all-time low in October 2010, the national MiMi has rebounded 39 percent, but remains significantly off from its high of 121.7.

So even DC has room for improvement (or room to grow another bubble, depending on how you look at it).

The Fast Pace of Rising Rents

Another factor behind the rent versus buy decision is not only the rental rates in an area, but also how fast those rates are increasing. What is affordable this year could well not be affordable in five years if rents are increasing at 6% a year.

A new rent forecast from Zillow offers good news to local area renters. The rate of appreciation is slowing. In fact, it is slowing throughout the nation but that also includes Washington DC, which to date has had a very robust multifamily sector.

Zillow predicts local rents will rise by 0.5 percent this year, from a median $2,107 to $2,118.

Washington DC, though, is still a very pricey market as you can see when it stacks up against the national stats. National median rent at the end of 2015 was $1,381, and is expected to increase slightly to $1,396 over the next 12 months, according to Zillow.

Rent appreciation will level off over the next 12 months, slowing to an annual rate of 1.1 percent by December 2016, it said.

And indeed, Zillow makes a point of saying even if the pace of rent appreciation decelerates, rents are still unaffordable for many income levels in certain cities.

Renters in San Francisco and Los Angeles can expect to spend 40 percent of their income on a rental payment, for instance.

"Hot markets are still going to be hot in 2016, but rents won't rise as quickly as they have been," said Zillow Chief Economist Svenja Gudell. "The slowdown in rental appreciation will provide some relief for renters who've been seeing their rents rise dramatically every single year for the past few years. However, the situation remains tough on the ground: rents are still rising and renters are struggling to keep up."

These two data points don't make the decision of rent versus buy any easier, but they do shed some light of what the future in both markets might look like.