Unless you've been living under a rock for the last several years, you've probably noticed how difficult it is to sell real estate in this miserable market. For most real estate investors, this means that the most lucrative way to invest is to buy now while prices are low, and hold for the long term using a lease agreement to wait until the market is warmer again. Put another way, it's a market for "safe" investing, not quick, lucrative contract flipping.

While all investing, whether rental or otherwise, involves some degree of risk, there some patterns of real estate appreciation that can be relatively predictable over time. Here are a few ideas on what to look for, regarding geography, demography, and other predictors for long term real estate appreciation.

Water

Everyone wants to be near water, period. This may be the ocean, a lake, a river, a bay, or anything else that's wet, but the fact is that waterfront (or water view) property appeals to people wanting to boat, fish, swim, hunt, or simply view from their porch. There's a finite supply of waterfront land, and an ever-increasing demand to buy it, develop it, or sign a lease agreement for it, so it is a forever appreciating commodity. Beware, though, of flood plains and hurricane alleys, which may intensify with global climate change. These properties are already expensive to insure, and that will only grow worse with time.

Population

It doesn't take a macroeconomist to realize that as population in an area increases, so does demand for housing. Look for areas with long term projected population growth to invest in, and remember that while your mortgage costs will remain roughly stable, you can demand greater and greater rent in your lease agreement. As a final note, the fastest vector for population growth is immigration, not breeding, so keep that in mind when evaluating neighborhoods for rental investment.

Urban Planning

Towns and cities with poor urban planning result in disastrous suburban sprawl, which leads to urban decay as developers continue to build farther and farther outward. Strong urban planning, however, will strictly limit how and where developers build, which helps to limit housing supply, and helps encourage reinvestment in existing neighborhoods instead of simply building new ones. Consider a town's urban planning policies and efficacy before investing, as they will have a profound impact on housing values over the long term.

Stable Institutions and Employment Providers

Some employers are so massive, and so stable, that they create their own center of gravity with orbiting neighborhoods. Massive government/military complexes can sometimes create this effect, along with universities, hospitals, and other large-scale institutions. Find out where these employees like to live, research that institutions long term plans regarding expansion or relocation, and consider investing in these areas as they can secure you a long term lease agreement with a stable and invested tenant.

While this list is in no way exclusive, hopefully it will provide you some ideas in evaluating long term real estate investing, and places where a landlord might secure a long term lease agreement. Good luck, and remember to consider the big picture in long term investing.