Stack & Tilt: My Swing

Yesterday I went to GolfTEC and had a complementary swing analysis. One of the GolfTEC PGA pros took me through their G-swing system: (1) putting me into an electronic harness (from the front, it looks like the strap for a backpack in frame 2 above), (2) video recording and digitizing my swing, (3) analyzing my swing against Ernie Els and Tiger Woods, (4) making some initial suggestions for improvement and (5) suggesting a number of lesson packages. Here is the video of my current swing (the S&T Swing) vs. the suggested new swing (the Width Swing). What's funny about this is that the "new" swing was basically my old swing before I went to Stack & Tilt (S&T)!

Whether I go back to the future or not is an open question, but the video analysis did point out some obvious flaws in my S&T swing. The flaws are clearly covered in the S&T video, but somehow I wasn't able to translate what I knew into a solid golf swing. The S&T book suggests video recording of your swing but I doubt that I would have caught all the problems without an objective analysis. GolfTEC is clearly adding value.

Maybe you can find the problems in my swing by comparing the S&T Swing to the Width Swing. In the next few posts I'll take you through the GolfTEC analysis with some of my own commentary. There were a number of interesting and, for me unexpected, conclusions from the analysis.

Stent vs. Bypass: The Gold Standard Study?

The New England Journal of Medicine recently published the results of the SYNTAX trial (here), a multi-center, multi-country randomized clinical trial comparing percutaneous coronary intervention (PCI) with drug-eluting stents vs. coronary-artery bypass grafting (CABG). The study seems to suggest that more patients should be undergoing CABG since there was more revascularization in the PCI group (death rates at 12 months were the same, although stroke in the CABG group was higher). Let's take a closer look using the causal model of heart attacks discussed in an earlier post (here).

Consider first the problems of designing a true randomized clinical trial comparing a procedure (PCI) with an invasive surgery (CABG). You simply cannot randomly assign patients to either treatment condition. Many patients would prefer to avoid a seriously invasive procedure such as CABG and a few more patients would prefer to avoid any procedure at all. And, that's exactly what happened. From the hierarchy diagram above (click on the diagram to see an enlarged view) 1262 patients were found ineligible, the majority because they had a treatment preference (probably PCI). Another 1275 were eligible only to be placed in a parallel, nested registry where 1077 enrolled in CABG and 198 enrolled in PCI. In other words 2537 patients were not randomized compared to 1800 that were randomized.

As a practical matter, self-selection cannot be avoided. As a consequence, study results really are only applicable to people that meet criteria (three-vessel or left main coronary artery disease) and had no treatment preference. It would be nice to know the rates of revascularization, mortality and stroke in the groups that were not randomized.

The study has a number of other limitations reported by the authors but no mention is made of the 12-month histories of cardiac rehabilitation in any of the groups. If there was no cardiac rehabilitation (e.g., substantially increased aerobic exercise), the rate of revascularization might be explained by that alone. If, for example, all 1800 patients were sedentary in the first 12 months, CABG may produce better outcomes. What cardiac rehabilitation, weight control or smoking cessation programs the PCI group went on (if any) is unclear. The issue isn't discussed in either the paper or the supplementary material, although my guess is that the standards of cardiac rehabilitation are very different in the countries that participated in the study.

On the basis of this study (and the other existing clinical trials reviewed in the paper), should treatment protocols change?

Russia is Burning

Shown above is a prediction for the year 2065 from the NOAA/GFDL CM2.1 Climate Model. Most of the World's land masses are predicted to be well above average temperatures for 1971-2000. What might be the consequences of global temperature change at this level?

Consider what is happening right now in Russia: This year, Russia recorded the hottest day (100 degrees) since record-keeping began in 1880. Wild fires continue to burn out of control. Smoke from the fires has substantially increased air pollution in Moscow. Russia's state environmental agency concluded in 2008 that Russia was warming twice as fast as the rest of the world. As a result of the heat and drought, Russia has banned the export of wheat while US wheat exports are booming.

Here's the causal model:

Positive signs on arrows are implied while two negative signs in a row (drought reducing the Russian wheat harvest which is negatively related to the US wheat harvest) are read as a positive impact (as discussed last week in Global Change). For good measure, throw in the floods in Pakistan (more energy in the atmosphere generating stronger monsoons).

Right now, the environment (especially climate change) seems to no longer be an issue in Washington yet, Russia is burning. In 2065, the NOAA model predictions for the US are not reassuring, but that's 55 years from now and elections are in less than two months.

The Russian ban on wheat exports is also creating the potential for a world-wide food crisis. The NY Times, in an editorial, asks that Russia learn from the last food crisis caused in part by demand for biofuels (another environmental issue) and not pursue "misguided polices". Imagine the rationality of policy making if world temperature increases by a few more degrees by 2065.

The Stimulus and Globalization

A recent editorial in the NY Times from the US Business and Industry Council argued that the government expenditure contained in the US economic stimulus package leaked away as consumers purchased imports from foreign countries. The council's suggestions: (1) buy American and (2) impose Tariffs. Each of these policy interventions can be analyzed using the causal model presented in an earlier post. Part of the causal model is displayed above (click on the graphic to see a larger image).

Government expenditure with a "Buy American" requirement would stimulate domestic sales, increase production, create jobs and create more demand (some of which would go to imports). Tariffs (taxes) on imports would make them more expensive and reduce demand.

Beggar-my-neighbor trade policies have been tried before. The Smoot-Hawley Tariff didn't work during the Great Depression and may have made things worse. But, the Business and Industry Council argues that tariffs worked during the Nixon Administration when, in 1971, Nixon imposed tariffs on Japan, Germany and other countries that refused to let their currencies rise. The tariffs were part of the Nixon Economic Shock (to include wage and price controls) in response to inflation generated by the Vietnam War.

Neoclassical economists argue that tariffs are a bad idea because they raise the price of domestic goods and damage the world economy. We would need a causal model of the world economy to discuss the later point (maybe in a future post). However, the effect of tariffs depends on what is being taxed. If we impose tariffs on countries with substandard environmental controls (green- or eco-tariffs), we benefit our own economy and benefit world environmental systems.

What do you think are the chances that the US Congress would impose tariffs? How about the chances that the US Congress would impose eco-tariffs?

The President's New Plan

It's getting close to the mid-term elections in the US and President Obama has a new plan for business tax breaks. Robert Reich gave a great commentary on NPR's Market Place and the commentary seemed to be based (with some embellishment) on the causal model above (click on the graphic for an enlarged view).

The president is proposing corporate tax cuts for R&D. Tax cuts will lead to the development of labor-saving technology that reduces jobs. Profits might also generate some investment (if there is demand). Otherwise, profits will be expended on CEO pay and Shareholder dividends which fuel the Stock Market casino (didn't that all start the Great Recession in the first place, that is, too much easy money sloshing around).

The problem we're having right now is inadequate demand created by the Great Recession (you can see the vicious circle in the graph: lack of demand leads to lack of sales leads to lack of production which leads to unemployment which decreases demand, etc.). Interest rates could be lowered by the Federal Reserve but they are almost at zero (the zero-bound) right now. Exports could be increased but the rest of the world is also in recession. Imports could be reduced (e.g., automobiles) but that requires demand for US products.

What remains is the Keynesian economic prescription: government spending. There is only one problem with increased government spending: it is being blocked by deficit hawks, fiscal conservatives, sound money evangelists, and bond vigilantes. The same dynamic played out during the Great Depression until WWII intervened.

So, the President's New Plan will be counterproductive (R&D tax cuts could decrease jobs), the Fed is at the zero-bound, and government expenditure will not increase unless we have another World War. What's going to happen?

Eventually, the markets will have their way and, in the words of Andrew Mellon (Herbert Hoover's Treasury Secretary), the markets will:

...liquidate labor, liquidate stocks, liquidate farmers, liquidate real estate… it will purge the rottenness out of the system. High costs of living and high living will come down. People will work harder, live a more moral life. Values will be adjusted, and enterprising people will pick up from less competent people.

For people that believe in markets and for people that do not, Mellon makes an important point. All markets will eventually adjust to bubbles created in other markets (e.g., housing and the stock market). The adjustments are brutal and painful if not necessarily swift. Subdivided ghost towns will be bulldozed or left to decay, jobs will be shipped to low-wage countries, companies will fail, people will drop out of the work force or take jobs below their skill level, and eventually there will be a new equilibrium.

The politics of all this are a little infantile: The US father figure (the president) is expected to fix the mess yet, at the same time that he is expected get out of the economy by reducing expenditure and regulation. I just heard another great Catch-22 in NPR Marketplace tonight: all the stimulus funds have not been spent because there are not enough federal workers to manage the contracts.

A Better Model of Heart Attacks

In a previous post, I presented a causal model of heart attacks and commented that the model could be improved. Pictured above is an improvement that specifically includes coronary artery blockage. Compare it to the excellent discussion and animation available from the National Institute of Health. The way to read this causal diagram is to look at the input variables and trace their effects through the system (as you are tracing a single path through the diagram, the effects are positive until you encounter a negative sign):

(1) Genetics (family history) and life style (overweight, smoking, diabetes, etc.) can lead to coronary blockage.

(2) Intervention in the form of a diagnosis can lead to either prevention, drug treatment or angioplasty and stents, all of which can reduce blockage and reduce the chance of heart attack.

(3) Heart attacks, however, can also be caused directly by shocks (e.g., taking cocaine, emotional stress or pain, exposure to extreme cold, cigarette smoking, etc.) or heart spasms (tightening of a coronary artery that cuts off blood flow through the artery--the causes of coronary artery spasm are not well understood).

The causal diagram above seems to capture the current understanding of heart attacks but it doesn't explain why you or a sample from the general population will have a heart attack and it doesn't predict which interventions will reduce the chances of having a heart attack. This is because there are too many back-door paths that can create a heart attack.

You could (1) have a heart spasm, (2) continue smoking, (3) drop out of your cardiac rehab program, (4) gain weight, (5) become diabetic, (6) become a drug addict, (7) stop taking your prescription medications, etc. etc. Out of all this, the only thing you can't change are your genetics or family history and the stents you may or may not already have in one or more coronary arteries. If angioplasty and stents don't prevent future heart attacks, as some research suggests, it does not mean the angioplasty is an unnecessary or ineffective treatment. There are simply too many back-door paths to that future heart attack to draw that conclusion.