Morgan Stanley (NYSE:MWD) is one of a handful of top-tier full-service brokerage firms and investment banks. It is involved in almost every conceivable aspect of financial services.

The firm announced second-quarter earnings this morning of $1.10, better than estimates of $1.06, and an increase of 100% versus the same quarter last year. Morgan cited continued strength from its fixed-income business and client growth in the Institutional Services division. It's not surprising that demand for banking services has increased because the economy is getting healthier.

Brokerage firms get a lot of bad press; most of it is probably deserved, and I think these firms bring a lot of it on themselves. Morgan Stanley has had its fair share of wrongdoing. Twenty years of industry experience leads me to believe that there will always be malfeasance, alleged or otherwise. Brokerage firms will almost always survive these episodes intact, with Drexel Burnham Lambert being an exception that proves the rule.

I learned in my time on Wall Street that very few accounts with less than $250,000 in investable assets are profitable. If Morgan lost all of that business, I believe profit margins would go up. Assuming it does not jettison all accounts smaller than $250,000, however, there are still many things that bode well for the future.

The need for our society to manage large retirement assets will only grow. Morgan Stanley will be a leader in underwritings (like it is for Google's IPO) for the next truly big thing, the last two big things being personal computers and the Internet. If (and this is a big if) any portion of Social Security money ever gets exposed to the stock market, Morgan Stanley will be there one way or another. The company has a huge global footprint helping to create new economic titans as emerging markets grow and possibly develop into industrialized nations.

Like it or not, investment banks are a play on economic growth. Scandals and fees notwithstanding, investment companies like Morgan Stanley, Merrill Lynch (NYSE:MER), and Goldman Sachs (NYSE:GS) will likely always do well.

Want to read more about financial companies? Check out these other articles from Roger Nusbaum:

Fool contributor Roger Nusbaum is an investment manager and wildland firefighter in Prescott, Ariz. At press time, his clients owned none of the stocks mentioned. As a former employee of Morgan Stanley, Roger still owns some shares but none of the other companies.