Sunday, September 18, 2011

What I learned... about Economics

This was easily my favorite class for several reasons. Primarily the professor, Dr. Gerald Swanson, renowned in his field and, like me, an "older" geezer-type, had a distinct way of relating to the young kids. He actually got them/me thinking about economics in very simple terms. It isn't complicated.

What is economics? It's an exchange. People engage in voluntary transactions they believe will make them better off. We usually think in terms of money: I have money and need a chair, you have a chair and need money. We exchange and everybody's happy. But economics can be about any exchange. I have a painting that you like, you have a chair that I like. If we both believe we will be better off with the other thing, we have an economic transaction.

Economics is a social science. It's all about human behavior. Human wants are insatiable - we all want more of something. Scarcity is a reality - we all have limited resources so we need to make good choices. Optimization is our goal; we want to maximize our well-being within the limits of our resources. I only have $50 to spend. What's the best chair I can get for $50? Or, can I get an adequate chair for just $30 and pocket the extra $20?

That's the thing about retail stores. Ideally retailers would never put the price on the things they're selling. Once they label something with a price, they're leaving money in the pocket of some consumers. Let's say I want to buy a pair of shoes and I'm willing to pay $80. So I go shopping. I find the perfect pair for $60. Only I know I'm willing to spend $80. If the shoe store owner could read my mind, he would have priced the shoes at $80 and we both would have been happy. Okay, we're both still happy, but he left me with an extra $20 that he could have gotten - he just didn't know it. But if he priced the shoes at $80 and the next person coming in the store could only pay $60, the retailer would also lose money because that person would walk out without buying.

As a retailer, how can I maximize my profit? By selling the same thing at different prices to different consumers. This is called price discrimination and is perfectly legal. Airlines do it every day. It doesn't cost the airline less to fly that plane on Tuesday, but they lower the price for people willing to fly on Tuesday because the airline is better off with a full plane at a lower price per ticket than a half-empty plane at regular price. Movie theaters have discounts based on age, time of day, student status, etc. They're called price-seekers - trying to find the maximum price each consumer is willing to pay.

Senior citizen discounts, coupons, limited-time offers, mail-in rebates - these are all examples of price discrimination. And once their fixed costs are covered, every additional sale is mostly profit anyway so it doesn't matter what they charge. This is why colleges have scholarships. Empty seats in a classroom can be filled at no additional cost to the university. They already covered their costs with tuition-paying students so the marginal cost of an additional student is zero! And the college gets to look noble and generous.

That's enough for today. But it's not the last you'll hear from me about economics. They should make this class a requirement for every student.

Thursday, August 25, 2011

What I learned: Arbitrage

I'd heard the word before without ever understanding it. Arbitrage is the ability to find identical investments that have differing prices and taking advantage of this disparity without risking a cent of your own money.

For example, if iPads are selling in the US for $500 but are only available in Europe for the equivalent of $600, you can borrow $500 from the bank, buy an iPad, sell it via the internet for $550, pay back the bank, and pocket the $50. You haven’t used a penny of your own money. If you owe any interest to the bank, it is probably minimal. This is arbitrage.

Monday, August 22, 2011

What I learned: Stock diversification


If you load up your investment portfolio with only tech stocks or only pharmaceuticals, for example, your risk level is high because what impacts one type of stock will likely impact all the other similar stocks. This is called independent risk, or idiosyncratic risk, and it’s completely unnecessary. You can virtually eliminate this risk – diversify it away – simply by having a minimum of 30 different types of investments in your portfolio.

A lot of folks who are interested in investing for the future also own a home. Of course a home is a great investment but, unless you’re a millionaire, you’re putting a whole lot of eggs in the same basket (subjecting yourself to idiosyncratic risk). This is especially true if you also own an index fund that is in REITs (Real Estate Investment Trusts) and maybe even own a second home for rental income.

Here’s how to find out how diversified you are. Take your net worth (assets minus your debts) and divide by 30. This is the theoretical maximum you should have in any single investment in order to be properly diversified. If your net worth is, say, $450,000 (including the estimated resale value of your home minus your mortgage balance), then the most you should be holding in real estate is $15,000.
However, if you’re like most Americans, your home is probably at least 40% of your portfolio. Add to that your REITs and that rental property, and you’re way under-diversified. If you don’t own a home, maybe you should just own $15,000 worth of REITs. It is, of course, a personal choice. Just keep this in mind when you consider the riskiness of your investments.

Monday, August 15, 2011

What I learned: About Curves

A “curve” in college is usually a straight line.

In Economics there are two curves: the demand curve and the supply curve. Draw both on a graph and you basically have an X. No one bothers to calculate the actual curve, if there is one.

Grade on the curve, or apply a curve at the end of the semester. This also means a straight line. Sure, the bell-shaped graph representing all the grades is curvy, but the cut-off point is still a straight line.

Had one prof who declared at the beginning of the semester that 25% of the class would get an A, 50% would get a B, and 25% would get a C. Period. Seems like a straight "curve" to me! Theoretically I suppose one could possibly do nothing other than register for his class and still get a C, but I wasn’t willing to find out. I got a B.

Saturday, August 13, 2011

What I Learned: Point-slope formula

Probably the biggest thing college did for me was in the area of math refresher. Ashamed to say I had let my math skills slip mightily over the years.

I know I probably learned this formula in high school but since there was a 30-year gap for me between high school and college, I guess I plumb forgot it!

The point-slope formula (also known as the slope-intercept equation) was the very first thing I learned in remedial math class. Those of us who failed the math assessment during student orientation had to take this extra class designed to get us up to speed before taking real college math.

First day of class Dr. Jessica Knapp (who looks nothing like a math teacher, by the way!) brought stacks and stacks of styrofoam cups and passed out maybe 10 or 12 cups to each group of 2 or 3 students. Our task was to construct a formula that would tell her how high the stack was. And the formula had to work even when she combined two of the stacks.

Some of the students got out their trusty ruler, measured one of the cups, and multiplied that by the number of cups. Okay, okay, I almost did the same thing. But then I noticed another measurement we needed to have. The distance between the lip of the first cup and the lip of the second.

So you really need TWO measurements in this formula. One will be used just once, and the other will be repeated as many times as you have cups. This is called the point-slope formula: y = mx + b

y is the height of the entire stack
m is the number of cups
x is the height of the lip
b is the height of the first cup below the lip

So the height of the stack is 12 (cups) x .5 (half an inch) + 4 (inches)

I can’t tell you how many times over the course of my four year college career this formula popped up. Over and over and over again - in economics, finance, statistics - everywhere. Very useful formula! I think it's magic in its simplicity.