Showing posts with label math. Show all posts
Showing posts with label math. Show all posts

Wednesday, October 31, 2007

Little Is Learned By Triathlon Survey

In yesterday's Capital, Nicole Young wrote a story reporting favorably on the overall reception of the triathlon by the citizens. I am acquainted with Ms. Young, and might have to send her a thank you card accompanied by a $5 gift certificate to Caffe Pronto for providing me with such good material. The article mixes 2 of this blog's favorite topics: statistics and the triathlon.

A major obstacle that can frustrate effective analysis is the misinterpretation of statistics. I have said before and shall reiterate--for most people, it's not very important to know how to derive, say, the formula for standard deviation. What is important is the ability to see where data is coming from, who is presenting it, and what certain statistics really mean.

And when the people interpreting the data make claims like these:....
City officials were surprised by the positive results
.
But the results speak for themselves. We were expecting the results to be
extremely negative, but they were saying 'We like the event, we'd like to see it
come back, but we'd like to see it done better,' which is OK.

.....it is important to assess whether this is actually the case.

Two surveys were taken of stakeholders in the triathlon, one by a firm called the Minor Group and another by the event itself.

First things first: the survey done by the triathlon's organizers is meaningless. According to the article:

The other (survey) was completed by the triathlon itself, which
surveyed the athletes, volunteers and spectators who participated in the
event.

Those participating in the triathlon responded favorably to the event,
with 83 percent calling the triathlon positive and 84 percent saying they would
participate again, the Annapolis Triathlon Club survey showed.


This is the definition of selection bias. Of course the people who participated in the triathlon are likely to think it was a success. I would bet that these numbers are way different than numbers that are collected from a randomized sample.

(Note to readers: in the interest of full disclosure, I had already seen the other numbers when I wrote the last sentence, so I knew I would be right! But it would have been fairly easy to predict.)

Now then:
According to the survey conducted by The Minor Group, businesses and
residents were split on the overall impact of the triathlon, with 34 percent of
businesses and 37 percent of residents saying it had a positive impact. The
number saying it was negative was slightly lower and undecided responses made up the remainder of the survey.

Luckily for us, based on these numbers we can group businesses and residents together, and don't have to analyze them separately. Otherwise this post would be unnecessarily long, and that's not good for anybody. Let's assume that the numbers go something like this:

-35% in favor
-30% against
-35% undecided

This is a lot of undecided's. It is probably accurate that 1/3 of people have no feeling either way. The issue here is the concept of sampling. Since it would be way to expensive and time consuming to survey all 40,000 city residents/people involved in the event, you have to take a sampling. Such a high portion of undecided responses means that were you actually able to survey everyone, it is more likely that the numbers would significantly change because you would be capturing everyone that has an opinion. And with the survey results so close, the majority faction could easily reverse.

Furthermore:
The whole thing was rushed through and didn't take into account all of the
people affected," he (
W1RA President Doug Smith) said. "The residents were next
to the bottom of the list and the churches were exactly at the bottom of the
list.

If accurate, this fact skews the data even more. Residents and churches are the most likely to oppose the event, and if they were not accurately represented, the true 'against' figure is higher.

So, in summary:

1. The survey done by the event itself should be used for kindling.

2. The 'random' survey quite possibly reflects data distortions resulting from sampling difficulties.

3. Since the only survey that matters is in fact too close to call--and not overwhelmignly positive--saying things like "but the results speak for themselves" and declaring resounding support for a future event is inappropriate when based solely on the surveys.

Friday, September 28, 2007

Chief Johnson Continues Emphasis On Community Partnerships

Speaking at a meeting of the Eastport Civic Association, Police Chief Johnson had this to say:

We don't have enough eyes and ears to make you safe.

While this makes a prima facie case to hire more officers, the actual meaning of this quote is certainly more pragmatic. The chief elaborates:

I learned early on, we (police) couldn't make a community safe by ourself (sic) . You will never hear me say no to a community group.

Make no mistake--short of a martial law, there will never be enough police to catch every crime. Communities, and individual families, are invaluable in crime prevention. My problem has been the tendency of the administration to place the entire burden on communities. I have been to city council meetings where several residents testified to crimes happening, and the mayor's response was 'form a neighborhood watch'. So long as there is indeed a partnership, the chief is absolutely correct.

We also learn in this article that 8 new officers were hired from an applicant pool of 95 that passed the entrance exam. I suppose that I should be happy that this information is known, but truth be told, I kind of annoyed that this answer could not be provided by the Public Information Officer or the Police Department Spokesman, both of whom I emailed.

I was not a math major, but let's give it a try:

22 vacancies in the department
+3 officers called to military service
+4 officers on maternity leave
-8 new officers that were hired
=
a staffing problem only equalled by my company.

This doesn't even take into account how many officers will be retiring, or the ratio of non-patrolling supervisors to patrol officers.

I can't help but ask, if 95 people passed the test, and there are at least 22 spots to fill, why did we only hire 8?

Thursday, September 20, 2007

Fuzzy Tax Math

As part of his rhetoric at the "kitchen table" unveiling of more details on new taxes, "Governor MOM" declared that 95% of taxpayers would save money under the new proposal.

First of all, the 5% who would pay more are, of course, the rich. I am not even going to go into the arguments as to why taxing the rich at a disproportionately high rate hurts precisely the poor and middle class people that people are trying to help, and instead focus on the fact that the 95% statistic is total balderdash in the first place!

(I recently learned that 'balderdash' is a synonym for 'nonsense', and I have been striving to use the word frequently.)

The current state tax code provides that all persons are taxed at a rate of 4.75% of income for all incomes over $3,000. Since almost everybody makes more than $3,000 per year, basically we all pay a 4.75% state income tax.

The new tax code makes some changes, but single persons making $15,000-$150,000 and married persons making $22,500-$200,000 still pay 4.75%!! The median household income in Maryland is about $53,000--this means that the average family is paying basically the same income tax!!!

AND, THIS IS ONLY THE INCOME TAX!! If you raise the sales tax by 20%, raise the gas tax by who knows how much, and expand the sales tax to include services--the real tax environment that we will be facing rears its true, ugly head.

In other words, if you keep income taxes basically the same, and increase every other tax, taxpayers will be worse off than before and will have less money to spend or save.

As Ron George says, "Only the governor could call a tax increase a tax cut."

Thursday, August 30, 2007

How To Measure Crime

I took 5 semesters of statistics throughout my academic career, which has caused me great trauma and will probably pay off in the long run for one lucky therapist. But, I have come to realize the value of statistics. It's not the ability to do the formulas, calculate alpha error percentages, or model bell curves--it's the practice of being 'statistically minded'. In other words, when you hear a fact or statistic, it is very valuable to be interested in how the information was calculated and if it indeed is an accurate representation of what you are trying to understand.

For elected officials, knowing the exact nature of a problem is the first step in finding the proper solution. (Think WMD's!) The major issue in the city of Annapolis is the crime, and the elected officials have spent much time--or at least paid much lip service--trying to figure out solutions.

We should take time to ensure we are measuring crime correctly. Just because arrests are going up, doesn't mean crime is getting worse. It could just mean we are getting better at catching the criminals. Similarly, if there are fewer arrests, it doesn't necessarily mean crime is decreasing; it may mean criminals are becoming more elusive.

I suppose the only 'statistic' that ultimately matters is our perception of quality of life. Do we feel safe everywhere in the city? Are we confident drugs are becoming harder to find? Data can be manipulated to say almost anything, and we have to be steadfast in our resolve to continue to fight our problems.

Friday, July 6, 2007

Do Your Math on the Sales Tax

Although the title of this blog, AP, refers to the politics of the city of Annapolis, from time to time state issues make their way onto these pages, as the state capital is indeed here as well.

So, the state budget issue goes something like this. Ehrlich came into office facing a budget deficit, then turned it around and left a $1 billion (fact check needed) or so surplus for O'Malley. O'Malley blew through that money in his first year, and now the state has no money, so they say. Politicians are now talking about what they call the 'doomsday budget', and telling us that if they don't raise taxes we will be cast back to the stone age because our schools, police, fire, and other services will just stop working. They are buttering us up for a HUGE tax increase next year, which is what happens when you have the executive branch and both houses of the legislature controlled by liberals. Note to readers: WE DO NOT HAVE A BUDGET PROBLEM, WE HAVE A SPENDING PROBLEM. REPEAT, A SPENDING PROBLEM!

Please read this article, in which Senate President Miller and House Speaker Busch talk about the budget and raising taxes. I am having you read this now, so next year, when all of this actually happens, I can make a cheeky 'I told you so' post on this site.

I am now going to quote selected excerpts from the article, and give you the no BS translation as to what this really means.

The sales tax is estimated to bring in $3.6 billion in fiscal 2008, according to the state. A 1 percent sales tax increase would raise an extra $750 million.

I hope you all like pop culture, because we are now going to play 'Are You Smarter Than A Fifth Grader?'!!! If the original value is 5, then it goes to 6, by what percent does it increase? Well, it's (6-5)/5 = 1/5 = .2 = 20%. THIS IS A TAX INCREASE OF 20%, NOT 1%. IT IS A 1% INCREASE OF THE VALUE OF THE GOOD, AND A 20% INCREASE IN WHAT YOU ARE PAYING. Let's use some numbers. Say you buy a car for $20,000. Now, you pay $1000 in sales tax. With a 6% sales tax, you would pay $1200. First, notice that this is a lot of money! Second, notice that you paid $1000, you now pay $200 more, and that is a 20% increase. This also means that the state will see A 20% INCREASE in sales tax receipts. Please write the papers when they call this a 1% increase.

But any sales tax hike would be part of a broader "menu" that would first look to cut state spending, reduce aid to local government, and then fill the remaining gap with new revenue, Mr. Busch said. Lawmakers have a duty to not unduly burden middle and lower class families with high taxes, he said.

Menu? A f_ _ _ ing tax MENU??!!! Let's get something straight, taxes are where the government (i.e. your neighbors who you elected) takes YOUR MONEY and gives it to SOMEONE ELSE for any reason they want. Democrats and liberals, you can now observe, see this as a natural part of life. They choose from a menu--a comprehensive list of dozens, perhaps hundreds, of ways to take your money. When one way produces less money, or invokes criticism, they just order something else from the menu. Also, remember Mr. Busch's promise not to burden middle and lower classes with higher taxes. First of all, rich families are apparently supposed to be unduly burdened with high taxes. And second of all, I promise you that he will raise taxes for EVERYBODY.

Last session, a bill sponsored by Del. Jim Gilchrest, D-Montgomery, would have taxed services ranging from auto repair shops and parking facilities to tanning salons and escort services.The legislation projected that state revenues could increase by more than $300 million in fiscal year 2008 and go up to more than $760 million by fiscal 2012.

I own a service based business in Prince George's County. What do you think will happen if I have to start paying sales tax (even though I am not selling anything). The cost pressures I face will cause me to either raise prices or decrease the quality of service, or put employees out of work. Somebody else, in another state right next to me, will come in and offer a better value and take business from me. Not only is this idea obviously bad for in-state businesses like mine, IT IS BAD FOR THE STATE ITSELF. This reasoning is a spin-off of the famous Laffer-Curve analysis of the optimal tax rate, which states that at some particular tax rate, an increase in that rate will actually cause a decrease in government tax revenue. Here's how: increases in tax rates increase the tax revenue per dollar of economic output (or GDP), but decrease the actual output itself. In my example, my income goes down because of the competing company who takes business from me. So, the state makes more money on each dollar of profit I make, but that profit is lower than before. At some point, the loss in profit outweighs the increased portion of tax I pay on the profit I still make, and the government therefore ACTUALLY LOSES MONEY BY RAISING THE TAXES. Not to mention, higher taxes may cause me to lay off employees because I can't afford to pay them, so the state loses this employee's income tax, and payroll taxes that I pay on the employee's salary.

I was recently denied admission to the University of Maryland PhD program in economics (who DO they let in? I graduated UMD cum laude in economics, started a freeking business at UMD, and was Young Entrepreneur of the Year. Geez.), but I have put a call in to my personal friend, the Dean of Behavioral and Social Sciences, to see if there is a data-based, calculated optimal tax level (an actual number, say 5.5% sales tax) that would maximize revenue. Conclusion: keep taxes as low as possible and let the private market do it's job.

Regardless of potential backlash, Mr. Miller said, lawmakers must have the political will to tell people what they need to hear, not what they want to hear.

Ha! Translation: lawmakers will tell us they are raising taxes no matter what and we can't do a damn thing about it even if we have a better solution or the majority of us don't want higher taxes.

If anybody wants to start a sister site, perhaps http://www.marylandpoliticsisfrustrating.blogspot.com/, (do not click here, it is not a real site), let me know and we can get together!