tag:blogger.com,1999:blog-118556722024-02-08T07:55:26.373-05:00Richard C YehThis is a competition for mind-share. May the best ideas win!Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.comBlogger23125tag:blogger.com,1999:blog-11855672.post-44686318998476479902010-03-07T16:31:00.009-05:002011-03-07T22:50:24.341-05:00A heuristic for retirement savings<blockquote><BIG>Most persons should save at least a quarter, perhaps as much as half, of their post-tax (i.e., "take-home") income.</BIG></blockquote><br /><P>Saving for retirement feels complicated, because there are so many decisions to make. The purpose of this essay is to enumerate a few rules of thumb I shall use for simplifying these decisions. I think there may be some social benefit in promulgating these heuristics if they produce more-sustainable retirement outcomes.</P><P>Thaler and Sunstein (Nudge, 2008) make several useful points in this area:</P><br /><ul><li>Economists disagree on exactly how much people should save for retirement.</li><li>Humans are lazy.</li><li>Default choices or settings are extremely powerful.</li><li>Many people, when surveyed, say that they would like to save more for retirement; and then fail to do so.</li><li>Tversky and Kahneman demonstrated how associations and references affect our judgement.</li></ul><br /><h4>References and Reality</h4><P>What is retirement? Television commercials portray bliss with vacations and Viagara. I suspect the average reality is quite different. A few years ago, at a hotel in Clearwater, FL, an old woman said, "Retirement isn't all roses." Indeed, retirement is just permanent unemployment. And when you are unemployed, the key drivers that determine whether you will remain solvent are:</P><br /><ol><li>How much money you have, and</li><li>How quickly, and for how long, you'll deplete that money.</li></ol><P>The first rule-of-thumbs I shall offer will be for part (2). Part (1) is left as an exercise to the reader.</P><br /><P>Companies selling financial products offer (but do not guarantee) to help you realize your dreams. Many provide some sort of calculator to help you estimate how much to save. While these calculators range from simplistic to sophisticated (some even with Monte Carlo simulations to obtain a distribution on investment returns), the biggest problem is that they offer no transparency or guidance on assumptions --- and the assumptions are critical. The default settings on several calculators imply that income needed in retirement can be less than current income, and your investment growth rate exceeds inflation by several percentage points. Both can be dangerous assumptions.</P><br /><P>On the income point, if you can hardly afford to take vacations now, there is no way that all the senior-citizen discounts will accrue to allow you to take any vacations on less income. If you maintain a car to commute to work, are you going to wait for the bus to visit the public library and supermarket? If you expect to finish paying a mortgage on your home, you should not forget to plan for increasing house-repair expenses, such as a new roof or water heater; if you rent, your housing costs are not going to decrease. If you are not one of the few C-suite executives, tenured professors, or government- or union-pensioners eligible for subsidized health insurance for life, you should start studying Medicare-related issues now. Otherwise, consider that private health-insurance quotes for a 60-year-old couple today range from $5,000 to $28,000 per year; and, in the past ten years, health-insurance premiums have increased at double the rate of inflation. There goes the prescription for Viagara. In summary, I think <B>you should plan to spend about the same amount of money each year in retirement as now.</B> (Moshe Milevsky: Your Money Milestones (2010) cites Modigliani for this idea of smoothing consumption.)</P><br /><ul><li><SMALL>Source: http://www.ehealthinsurance.com/, quotes for family health insurance for male born 1/1/1950 and female born 1/1/1952 in zip code 10022, retrieved 2/15/2010, ranged $400-2,300 per month</SMALL></li><li><SMALL>Source: http://money.cnn.com/2009/09/15/news/economy/health_insurance_costs/index.htm</SMALL></li></ul><br /><P>On the investment growth assumption, most persons should not expect to realize inflation-adjusted returns over 30 years in excess of the +6% (net of inflation but not taxes) annualized historical S&P 500 rate. And what of taxes? The historical inflation-adjusted rate may be appropriate for estimating pre-tax-with-tax-deferral (401(k) and traditional IRA) dollars, or post-tax-with-tax-free-growth (Roth 401(k) and Roth IRA) dollars, but may be as low as +3% or +4% in a taxable account. I shall provide an example in a postscript. I am not going to discuss the suitability or the moral implications of owning stock.</P><br /><h4>Savings Pipeline</h4><P>Now, how many years should you plan for? For Generation-Xers and Generation-Yers, life expectancy at birth was about 70-75 years; and there is a significant chance that you'll outlive the typical lifetime. I am roughly 35 now, and I think it's safe to estimate that I'll work 30 years and then live 30 years more.</P><br /><P><B>In this case, my savings in year 1 of my career will grow (or lay dormant) for 30 years, to be spent in year 1 of retirement. My savings during year 2 of my career will grow (or lay dormant) for 30 years, to be spent in year 2 of retirement.</B> And so on. With this pipeline, I calculated the below table to estimate the amount I need to save, given various inflation-and-tax-adjusted investment returns.</P><br /><table><br /><tbody><tr valign="BOTTOM"><th rowspan="3">If you expect your savings to grow, compounded, by this percent each year after subtracting inflation and taxes,</th><th colspan="5">then, to have the same annual budget in retirement as now, assuming a schedule (years of work/years of retirement) of</th></tr><br /><tr valign="BOTTOM"><th>30/30</th><th>40/20</th><th>45/15</th><th>48/12</th><th>50/10</th></tr><br /><tr valign="BOTTOM"><th colspan="5" align="LEFT">your savings rate should be:</th></tr><br /><tr><td>-4%</td><td>77%</td><td>72-53%</td><td>68-38%</td><td>64-29%</td><td>61-23%</td></tr><br /><tr><td>-2%</td><td>65%</td><td>52-43%</td><td>45-31%</td><td>40-24%</td><td>35-20%</td></tr><br /><tr><td>0%</td><td>50%</td><td>33%</td><td>25%</td><td>20%</td><td>17%</td></tr><br /><tr><td>+2%</td><td>36%</td><td>18-25%</td><td>12-20%</td><td>9-16%</td><td>7-14%</td></tr><br /><tr><td>+4%</td><td>24%</td><td>9-19%</td><td>5-16%</td><td>4-14%</td><td>3-12%</td></tr><br /><tr><td>+6%</td><td>15%</td><td>5-13%</td><td>2-12%</td><td>2-11%</td><td>1-10%</td></tr><br /></tbody></table><br /><br /><P>To read this table, let's imagine you can invest in a 30-year certificate of deposit (CD) that returns 0% above inflation and taxes. (This product doesn't exist, but you may be able to simulate it with I bonds or TIPS. I am not going to discuss the suitability or the moral implications of owning government debt.) Then, for every $1.00 you put into the CD, you can withdraw $1.00 (today's dollars) 30 years from now. If your current post-tax income is X, you can simulate a future budget now by saving 50% of X (leaving 50% of X). If you are comfortable with the 50% you can spend today, then your lifestyle will not need to suffer much adjustment when limited to the saved 50% available in 30 years. If you save less of your income now, you are leaving yourself less to spend in retirement. You can vary your assumptions by considering:</P><br /><ul><li>Perhaps you will plan to work for 40 years and retire for 20 years. Then you can use two years of savings for each year of retirement, and (based on the same 0% tax-free, inflation-adjusted growth assumption) you could start by saving 33%. Why not 25% --- half of 50%? If you save 25%, then you are giving yourself a budget of 75% during your work years, but only 2 * 25% = 50% for each year of retirement, which violates the rule-of-thumb I suggested above. The other columns of the table show the needed savings rates for two, three, four, and five years of savings per year of retirement. Where there are percentage ranges, they indicate the saving rates needed in the first and last years of the non-retirement period. If you are saving 15% now, you are on a frontier hoping for a +6% annualized return on the 30/30 (years of work/years of retirement) schedule, or planning for the 50/10 schedule and with a 0% annualized return.</li><li>Perhaps you will have access to investments that return more than 0% after inflation and taxes. Good luck with that.</li><li>Perhaps you will receive Social Security payments or a pension. Good luck with that.</li></ul><br /><P>Changes in these assumptions can modify the savings fraction by perhaps a factor of two or three, but the conclusion is still robust: you should save a substantial fraction of your income.</P><br /><br /><P>To summarize, I am using two heuristics to estimate retirement savings:</P><br /><ol><li>Retirement income requirements are the same as now.</li><li>Using the savings pipeline and a conservative investment returns assumption, I must save a quarter to a half of post-tax income.</li></ol><br /><h4>Pre-tax or post-tax?</h4><P>In the above discussion, I've tried to use all post-tax, inflation-adjusted numbers. This is partly because it would be difficult for many persons to save 50% of their pre-tax income.</P><br /><P>When it comes to retirement investing under United States laws, one often has three choices: (1) pre-tax funds with tax-deferral (401(k) or traditional IRAs), (2) post-tax funds with tax-free returns (Roth 401(k) or Roth IRAs), and (3) post-tax funds with taxable returns (depending on choice of investment vehicle). The benefits of (1) and (2) are that taxes are a one-time cut, either (1) at the time of withdrawal or (2) before investment; while in case (3), taxes not only take the the same one-time cut, but also reduce the realized return each year. For example, if over 30 years, your investment returns 4% each year with 3% inflation, the inflation-adjusted return will be 1% = 4% - 3%; if taxable each year with a 25% tax rate (on the 4% earned), your real return would be zero, but if taxed only at the end with the same 25% tax rate, your real return would total 26%, or about 0.77% per year. The disadvantages of (1) and (2) are that they come with restrictions on the amounts you can save and the conditions under which you can take a penalty-free withdrawal. The only difference between (1) and (2) is whether you expect your future tax rates to be higher or lower than now, and if you aren't sure, you can hedge by dividing your saving between them.</P>Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-83059839626232602792009-05-28T01:55:00.002-04:002009-05-28T02:22:16.802-04:00Competition for mind-shareAt the encouragement of a friend, I have decided to give blogging another try. I recall that daily writing as a high-school senior helped sharpen my thinking; and I hope it will again now.<br /><br />I have changed the subtitle of this blog from "ideas scrapbook" (where I was using it as a bookmarking tool) to "competition for mind-share". Resolved: we must publicize nascent ideas clearly so that they can be criticized. This may be one personal blog out of thousands, but I hope to bring my own brand of logic, judgement, compassion to improve the signal-to-noise ratio in the blogging universe. I welcome comments.<br /><br />If writing in this blog sharpens my thinking and makes me a better person, then it will have been successful. If this blog collects a significant following, then it will have been wildly successful.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-83030008542554808412008-07-19T22:51:00.001-04:002008-07-19T22:51:27.635-04:00AntarcticaWatched "Encounters at the Bottom of the World". Also saw <<br><a href="http://www.emilystone.net/uploads/Cold_Comfort.pdf">http://www.emilystone.net/uploads/Cold_Comfort.pdf</a> >Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-53324198384809396082008-06-13T23:17:00.001-04:002008-06-13T23:19:30.742-04:00A Remarkable Tornado Photo<p><a href="http://thelede.blogs.nytimes.com/2008/06/13/a-remarkable-photo-from-tornado-country/index.html?partner=rssnyt&emc=rss">"The Lede: A Remarkable Tornado Photo"</a></p><p><small>An Iowa woman snaps a stunning close-up of a looming funnel cloud.<br /><br /></small></p><p></p>Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-91061086837461017142008-06-13T17:26:00.001-04:002010-11-30T22:40:14.237-05:00Kalman filtersConsider these for noise rejection, especially when moving to continuous-time data.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-67890833174538302532008-06-09T18:48:00.002-04:002012-11-15T00:51:52.400-05:00Link: tricks/techniques to accelerate normalized cross-correlation for image analysis<a href="http://www.cs.ubc.ca/research/deaton/remarks_ncc.html">http://www.cs.ubc.ca/research/deaton/remarks_ncc.html</a>Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-23915150268492439052008-05-07T23:39:00.002-04:002008-05-07T23:43:43.015-04:00FFT Window referenceshttp://www.lds-group.com/docs/site_documents/AN014%20Understanding%20FFT%20Windows.pdf<br />http://www.bores.com/courses/advanced/windows/files/windows.pdf<br /><br />The first link has a table with window characteristics:<br /><br /><blockquote>Window / Best for these Signal Types / Frequency Resolution / Spectral Leakage / Amplitude Accuracy<br />Barlett: Random / Good / Fair / Fair<br />Blackman: Random or mixed / Poor / Best / Good<br />Flat top: Sinusoids / Poor / Good / Best<br />Hanning: Random / Good / Good / Fair<br />Hamming: Random / Good / Fair / Fair<br />Kaiser-Bessel: Random / Fair / Good / Good<br />None (boxcar): Transient & Synchronous Sampling / Best / Poor / Poor<br />Tukey: Random / Good / Poor / Poor<br />Welch: Random / Good / Good / Fair<br /></blockquote>Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-40710484155610727412008-05-07T19:39:00.002-04:002008-05-07T19:46:18.317-04:00A. O. Scott: Here Comes Everyboy, Again"Mr. Sandler did not invent the archetype of the overgrown man-child, which has been around at least since the silent era. ... Nor has Mr. Sandler been alone, over the past 15 years or so, in turning male infantile aggression into the basis of a lucrative and long-running movie career. His rivals and confreres have included <a href="http://movies.nytimes.com/person/11257/Jim-Carrey?inline=nyt-per" title="">Jim Carrey</a>, <a href="http://movies.nytimes.com/person/195232/Jack-Black?inline=nyt-per" title="">Jack Black</a> and <a href="http://movies.nytimes.com/person/224449/Will-Ferrell?inline=nyt-per" title="">Will Ferrell</a> — all of them different physical and temperamental types, but all of them committed to a brazen and unyielding refusal of maturity."<br /><br />Add to this list the television comedies Seinfeld, Friends, Everyone Loves Raymond, and most recently, King of Queens. I had wondered about the provenance of this archetype, and the exact nature of the thing that so repulsed me about those shows, until this essay put a name to the phenomenon.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-63739637325024012382008-04-03T23:27:00.001-04:002008-04-05T02:08:49.391-04:00DoG is used in waveletsJust noticed that derivative of gaussian is also called "DoG" when used as a wavelet basis function. But I think Daubechies are more popular.<br /><blockquote style="color: rgb(0, 0, 153);">Are you using those in your price models?<br /></blockquote>Maybe in the future. One of my coworkers is using Daubechies wavelets in his model; compared with ordinary moving-average smoothing, doing a wavelet transform, cutting off the spectrum, and then transforming back seems to offer better noise reduction with less information. You still need a power-of-two data length, like for fast Fourier transforms.<br /><br />Recently, I have been using techniques from "robust statistics": medians, trimmed data, etc. This reminded me of our early experiences with median filtering. Now I think that, while the technique may be nonlinear, the point of experimental science is to make a reliable measurement. If the number itself is what we want to measure (or even ordinary arithmetic transformations thereof), then I say filter. I think the only case where I wouldn't automatically reach for a trimmed mean (where the top and bottom x% of observations are excluded before taking the mean) is if I were doing transformation to a different space, such as FFT. But for dynamic pulling experiments, I suspect FFT is a rarely-used technique.<br /><br />You probably know that the reporting of a standard deviation is only meaningful if the data are close to normal. Especially in the kind of data I have, I am plagued by fat-tailed distributions, and find that ordinary means and variances are too sensitive to outliers. The robust alternative is the MAD (median absolute deviation).Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-44058110489134681512008-04-02T22:51:00.001-04:002008-04-05T02:07:27.158-04:00Database Monte Carlo (DBMC): A New Strategyfor Variance Reduction in Monte Carlo SimulationMonday, March 31st,2008<br />10:00 am - 11:00 am<br /><br />CNLS Conference Room (TA-3, Bldg 1690)<br /><br />DataBase Monte Carlo (DBMC): A New Strategy for Variance Reduction in Monte Carlo Simulation<br /><br />Professor Pirooz Vakili<br />Boston University<br /><br />A well-known weakness of (ensemble) Monte Carlo is its slow rate of convergence. In general the rate of convergence cannot be improved upon, hence, since the inception of the MC method, a number of variance reduction (VR) techniques have been devised to reduce the variance of the MC estimator. All VR techniques bring some additional/external information to bear on the estimation problem and rely on the existence of specific problem features and the ability of the user of the method to discover and effectively exploit such features. This lack of generality has significantly limited the applicability of VR techniques.<br /><br />We present a new strategy, called DataBase Monte Carlo (DBMC), which aims to address this shortcoming by divising generic VR techniques that can be generically applied. The core idea of the approach is to extract information at one or more nominal model parameters and use this information to gain estimation efficiency at neighboring parameters. We describe how this strategy can be implemented using two variance reduction techniques: Control Variates (CV) and Stratification (DBMC approach can be used more broadly and is not limited to these two techniques). We show that, once an initial setup cost of generating a database is incurred, this approach can lead to dramatic gains in computational efficiency. DBMC is quite general and easy to implement -- it can wrap existing ensemble MC codes. As such it has potential applications, among others, in ensemble weather prediction, hydrological source location, climate and ocean, optimal control, and stochastic simulations of biological systems.<br /><br />We discuss connections of the DBMC approach with the resampling technique of Bootstrap and the analysis approach of Information Based Complexity.<br /><br />LANL Host: Frank Alexander, ADTSCRichard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-42704675392447540912008-02-11T22:59:00.000-05:002008-02-11T23:01:43.057-05:00Liars' PokerAfter reading Michael Lewis's Liars' Poker, and Roger Lowenstein's When Genius Failed, I am struck with a thought: make a program to play Liars' Poker. Either decimal or dice systems. Bayesian estimation of probabilities. Python.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-65492280509758601442007-11-26T14:25:00.000-05:002007-11-26T14:27:50.062-05:00Citation software - the next generationZotero < <a href="http://www.zotero.org/">http://www.zotero.org/</a> ><br /><br />CiteULike < <a href="http://www.citeulike.org/">http://www.citeulike.org/</a> ><br /><br />Del.Icio.Us < <a href="http://del.icio.us/">http://del.icio.us/</a> >Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-59013686553080556782007-11-20T23:35:00.000-05:002007-11-26T09:33:36.430-05:00Unemployment benefitsThe on-line application at the <a href="http://www.labor.state.ny.us/ui/ui_index.shtm">New York State Department of Labor Unemployment Insurance</a> web site is only available "between the hours of 7:30 am to 7:30 pm Monday through Thursday (Eastern Time), Friday, 7:30 am to 5:00 pm, all day Saturday, and Sunday until 7:00 pm."<br /><br />Bank of America / 100 Corporate Place, Suite 403 / Peabody, MA 01960 // EIN 56-2058405 NY 562058405<br /><br />212-583-8000<br /><br />Lockheed Martin NV Tech, Inc. / PO Box 98521 / Las Vegas, NV 89193-8521 // EIN 88-0347976 NM 02-297731-007Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-1145246683476825562007-11-19T14:54:00.000-05:002007-11-19T21:19:25.550-05:00Working with recruitersWhat is the value of working with recruiters?<br /><ul><li>Some have inside contacts (hiring managers).</li><li>Some have relevant information (company X has a hiring freeze).</ul>Coverage is spotty, though, and big firms tend to have established paths through human resources.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-87902583788474738872007-11-19T14:50:00.000-05:002007-11-26T09:31:09.844-05:00after-Thanksgiving sales"Black Friday" advertisements can be found at <a href="http://bfads.net/">http://bfads.net/</a> and <a href="http://www.fatwallet.com/">http://www.fatwallet.com/</a>. Mentioned in last Sunday's New York Times.<br /><br />This year, there doesn't seem to be anything special.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-70355037027812479092007-11-19T09:53:00.000-05:002007-11-19T14:49:46.934-05:00Electronic Lab Notebook (ELN) thoughtsMy ideal electronic lab notebook would:<br /><br /><ul><li>store everything in real time: I would like to paste in observations, measurements, complete data-processing histories, paper reprints;<br /></li><li>allow search for: free-text, creation date range, citation date range, citation count<br /></li><li>allow by-owner stateful highlighting of important things and collapsing of unimportant things: this would facilitate future review without permanently losing observations considered irrelevant at the time. An outline structure would probably be fine, but I would want to be able to collapse or expand any paragraph at any level.<br /></li><li>allow annotated hyperlinks to prior paragraph-level observations and dates in this notebook and others, for backwards-referencing;<br /></li><li>automatically count citations (i.e., this "observation was confirmed/rejected" or "protocol was reused" or "data was commented-on" on such-and-such entry) (the two points above combined mean that comments on previous observations, where the comments are actually new ELN entries, remain in-context);<br /></li><li>I don't see that entries more than two hours old ever need to be edited again, so don't provide an "edit" feature.<br /></li><li>treat protocols in a special way, somewhat like a source-code control or versioning system. When protocols are mature, it is easy for people to say: I used protocol ABC. However, over the course of years, there could be modifications to protocol ABC that could improve yield, save time, etc. Often, people will continue to say that they used protocol ABC. I would propose that every protocol's "permalink" should contain its version number, so that past links to protocol ABC would point to the historical ABC, not the new-and-improved ABC. Actually, this can be easily handled in the above scheme: just have the complete protocol as an entry; when the protocol is revised, then users of the newer protocol will link to the newer entries. This can be organized with a special "kprotocol" keyword, or a separate "Lab protocols" ELN where protocol developers have write access.<br /></li></ul>The GUI should facilitate easy linking, perhaps through endnotes for each entry.<br />When reading, the blog-like "Comment" button would become an "Add new entry to your own ELN" button, with the specified paragraph already referenced. <br />When writing, typing a special link string (such as double open braces) should bring up an in-page pop-up allowing search or selection of recently-cited and most-popular ELN citations. While we're at it, this should also allow web search and pasting of URLs or page snapshots.<br /><br />Discovered that this is an old idea: <a href="http://pubs.acs.org/hotartcl/ci/00/jan/inet.html">http://pubs.acs.org/hotartcl/ci/00/jan/inet.html</a>.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-12840608253702921832007-11-18T15:12:00.000-05:002007-11-18T15:29:35.646-05:00Income growth and house-price growth: phase portraitsDerek Cheung mentioned last May that his brother observed income as a leading indicator for house prices in Hong Kong. Zhang Da Peng's blog is at <a href="http://dpz88.spaces.live.com/">http://dpz88.spaces.live.com/</a>.<br /><br />Now we have data to explore this in the United States.<br /><br />Standard&Poors/Case-Shiller home-price indices for metropolitan areas are available at <a href="http://www2.standardandpoors.com/portal/site/sp/en/us/page.topic/indices_csmahp/0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0.html">http://www2.standardandpoors.com/portal/site/sp/en/us/page.topic/indices_csmahp/0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0.html</a>.<br /><br />The Internal Revenue Service's Statistics of Income Division <a href="http://www.irs.gov/taxstats/index.html">http://www.irs.gov/taxstats/index.html</a> has state- and zip-code-level sums of adjusted gross income and exemption sums. One problem with the zip-code-level sums is the cost: $500 per year for the whole United States.<br /><br />Phase portraits (y = momentum; x = position) can show the behavior of a damped driven harmonic oscillator in different regimes: simple undamped is a circle; underdamped spirals clockwise to the origin; resonance spirals clockwise outward. If we plot inflation-adjusted income growth on the x-axis and inflation-adjusted house-price growth on the y-axis, then counter-clockwise motion would mean income leads housing. I suspect driven or undamped behavior in the first quadrant, and damped behavior in the other three quadrants.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-77459518460049491252007-11-18T15:01:00.000-05:002007-11-18T15:12:07.164-05:00Essay idea: stickiness of housing and job marketsThe value of skills in the job market is always backwards-looking, just like comparable sales in a housing market. I have forgotten where this essay idea was going, but I think it was going to be a personal essay about going to work on mortgage-backed securities, learning about house-price appreciation, and then trying to find work elsewhere in finance.<br /><br /><br /><blockquote>"A great programmer might be ten or a hundred times as productive as an ordinary one, but he'll consider himself lucky to get paid three times as much. ... this is partly because great hackers don't know how good they are. ... it's also because money is not the main thing they want." (Paul Graham, "Great Hackers", July 2004, <a href="http://paulgraham.com/gh.html">http://paulgraham.com/gh.html</a>, in <i>The Best Software Writing I</i>, edited by Joel Spolsky (Apress, 2005))</blockquote>Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-72314248964648083532007-11-18T14:54:00.000-05:002007-11-18T14:59:53.431-05:00Blogs and Wikis againJust finished reading <i>The Best Software Writing I,</i> edited by Joel Spolsky (Apress, 2005).<br /><br />On pp. 197-198, I read of an idea of running an instant messenger and a wiki in parallel with a conference or conference. The link is: <a href="http://www.shirky.com/writings/group_enemy.html">http://www.shirky.com/writings/group_enemy.html</a>, about halfway down (search for "modes") Each presenter could have her or his slides on the wiki, and interesting questions and comments from the real-time chat could be added. The wiki would then become an annotated proceedings.<br /><br />With big-enough screens, you could see everything: instant-messenger chatroom, wiki, and external reference with browsing history.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-24318260385653424122007-11-18T14:44:00.000-05:002007-11-18T14:54:36.432-05:00New mission for blogPreviously, I had no use for this blog. Now I see that it can be a useful content management system for annotating my web-browsing history. It is more suited for my purposes than a wiki: I anticipate that I will generate only a handful of posts per week, so I don't need a big management or organization system. Since so many resources to be referenced are available from the web, this is more in-context than other forms of scrapbooking software. Finally, unlike many wikis, it's free for multiple users and I don't have to administer it.<br /><br />For now, I will change the name from the solipsistic paean "A song I can sing in my own company" to "Richard C Yeh et al".Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-4777816893107271442007-02-04T00:12:00.000-05:002007-02-04T14:30:48.326-05:00Test linkLink to network share via UNC \\Dice\Test: <a href="file://///Dice/Test/">file://///Dice/Test/</a>. (Works in Internet Explorer 7, but not Firefox 1.5.0.9 and not Opera 9.10.)<br /><br />Link to network share mapped as drive Z: <a href="file:///Z:/">file:///Z:/</a>. (Same as above, if mapped. Example 1 doesn't require the mapping to be in place.)<br /><br />Link to local file: <a href="file:///C:/ipconfig.txt">file:///C:/ipconfig.txt</a>. (Always fails, if web page is not a local html file.)<br /><br />Try this now:<br />1. In Windows, go to Start -> Run... and in the dialog, type:<br /> cmd /k ipconfig /all > C:\ipconfig.txt<br /> This will create a file for testing.<br />2. Paste this into your web browser:<br /> file:///C:/ipconfig.txt<br /> This should display the file.<br />3. In the wiki, make a link to:<br /> file:///C:/ipconfig.txt<br /> View the wiki, and click on the link.<br /><br />If nothing happens in step #3 (which is behavior different from step #2), then you are experiencing a problem described at: < id="9601">. I find that I can replicate this problem with Microsoft Internet Explorer 7, Mozilla Firefox 1.5.0.9, and Opera 9.10. I find that I can work around this problem in Internet Explorer, but not the other two.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-32138025693018632322007-02-03T21:45:00.000-05:002007-02-04T01:21:29.387-05:00Blogs and WikisAfter a good friend mentioned his ideas of using blog and wiki technologies in his new lab, I couldn't resist trying these again, in the hope that I'll better understand the possibilities of these. At work, I've documented some oft-used database tables and queries on the group wiki pages, served by Atlassian Confluence, which also runs the technology bug/issue-tracking system. Atlassian also has a blog feature, which I am trying to use to highlight developments in my work.<br /><br />Away from work, I tried to install my own wiki on a server where I have no administrative privileges, but there are many configuration questions that I cannot answer. I told my friend that there would be significant effort in setting up and maintaining such a system, and I am happy to hear that he found a solution at http://openwetware.org/.<br /><br />I am always impressed at the efficiencies to be wrung from outsourcing. For example, I think the Google Apps for Education product in use at Arizona State University is a good example to follow. There is much duplication of information technology effort across organizations, and consolidating and outsourcing those efforts could improve the quality and reduce the cost. I recall considering the purchase of a network-attached storage device and backup system for a research group where I was a graduate student. There's no educational value in that exercise. IBM's attempt to sell compute time is also notable, but has a smaller market, which probably needs time to play and explore. Drucker would have applauded our giving the problem to an expert to handle.<br /><br />References:<br /><ul><li><a href="http://www.google.com/a/help/intl/en/edu/customers/asu.html">Google brochure</a><br /></li><li><a href="http://www.asu.edu/news/stories/200610/20061010_asugmail.htm">Arizona State University news posting</a></li></ul>Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0tag:blogger.com,1999:blog-11855672.post-1112380262630169872005-04-01T13:30:00.000-05:002005-04-01T13:32:30.816-05:00I am such a fool --- to worry as I doWhy a weblog, and why now? A test of popular technology, to see if the shoe fits. An evaluation of a medium, to see whether it can be any more than a narcissistic, solipsistic indulgence.Richard C. Yehhttp://www.blogger.com/profile/02874507457884604159noreply@blogger.com0