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	<title>Ivan Jureta</title>
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		<title>Unclear public opinion surveys fill the media space easily and cheaply</title>
		<link>http://jureta.net/unclear-public-opinion-surveys/</link>
		<comments>http://jureta.net/unclear-public-opinion-surveys/#comments</comments>
		<pubDate>Fri, 11 Jun 2010 09:45:18 +0000</pubDate>
		<dc:creator>ivanjureta</dc:creator>
				<category><![CDATA[All]]></category>

		<guid isPermaLink="false">http://jureta.net/?p=229</guid>
		<description><![CDATA[


What? Gallup, a well-known public opinion survey firm, reports the results of a pool which suggests that &#8220;federal government debt&#8221; is the second most important &#8220;threat to U.S. future wellbeing&#8221;.
How? Gallup does telephone interviews with a random sample of about 1000 people from across the USA.
Why is this a problem? Such results cannot be reliable, [...]]]></description>
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<li><strong>What?</strong> Gallup, a well-known public opinion survey firm, reports the results of a pool which suggests that &#8220;federal government debt&#8221; is the second most important &#8220;threat to U.S. future wellbeing&#8221;.</li>
<li><strong>How?</strong> Gallup does telephone interviews with a random sample of about 1000 people from across the USA.</li>
<li><strong>Why is this a problem?</strong><br/> Such results cannot be reliable, because the issues in question (the items on that list) are vague and aggregate so many more specific issues that answers people give cannot be meaningfully aggregated. In short: my conception of &#8220;federal government debt&#8221;, or of &#8220;terrorism&#8221; is different than yours, and 1000 randomly chosen people certainly do not agree on the definitions of these notions.</li>
<li><strong>Takeaway:</strong> These pools are obviously not to be taken seriously. They serve best as ads/PR for Gallup, and to fill up time/space for those reporting them, like CNN and USA Today.</li>
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<div>Sources:</div>
<ol>
<li><a href="http://en.wikipedia.org/wiki/The_Gallup_Organization" target="new">Gallup:</a> <a href="http://www.gallup.com/poll/139385/federal-debt-terrorism-considered-top-threats.aspx" target="new">Federal Debt, Terrorism Considered Top Threats to U.S.</a></li>
<li>F. J. Fowler, Jr. <a href="http://www.jstor.org/pss/2749171" target="new">How Unclear Terms Affect Survey Data</a>. <em>Public Opinion Quarterly</em> 56:218-231, 1992. <a href="http://www.soc.iastate.edu/soc522a/PDF%20readings/Fowler.pdf" target="new">Free version is here.</a></li>
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<p>Survey questions should be clear. When asked a survey question, the person should know what this question refers to &#8211; what situations, events, people, objects, and so on &#8220;it is about&#8221;. Ideally, the person should know <em>exactly</em> what the terms and the ideas conveyed by the questions and offered answers refer to.</p>
<p>There is evidence ([2] is an example) that different phrasings of questions can result in statistically significant differences in responses to these questions. Simply put, if the &#8220;same&#8221; question is asked differently in two different surveys, the two surveys will result in different results and most importantly, give different conclusions (if the differences were not statistically significant, conclusions would remain the same for most practical purposes).</p>
<p>When survey questions/answers are not clear, different people will interpret the questions/answers differently. It only follows that different people will effectively understand different questions and thereby give different answers. This is the case in the Gallop&#8217;s pool &#8211; it&#8217;s results are shown below.</p>
<p><a href="http://jureta.net/wp-content/uploads/2010/06/Perceived-Threats-to-U.png"><img src="http://jureta.net/wp-content/uploads/2010/06/Perceived-Threats-to-U.png" alt="" title="Perceived Threats to U" width="500" height="369" class="alignnone size-full wp-image-232" /></a></p>
<p>A survey aggregates (for example, sums up) answers by types (then divides these sums by the total number of responses to get percentages), or otherwise, and presents these summary results. This is what surveys are for. However, it is obvious that if same answers are the result of different interpretations of the same question (and hence, of different questions), they lose in relevance: <em>the value of the information a survey gives is reduced, occasionally to no value whatsoever, or worse, it is misleading</em>.</p>
<p>Exact reference is very hard to accomplish. This is well-known. It is also an easy, but still relevant attack that can be directed at many surveys. It is a problem that, at least in published research, must be discussed at length to persuade other researchers and interested parties that enough rigorous tinking went into the design of the questions and of the possible answers.</p>
<p>Survey questions can be unclear because ambiguous or vague (there are other reasons as well, but let&#8217;s stick to these). A question is ambiguous when it can be interpreted in different ways, and this is a huge problem when alternative interpretations are contradictory. Terms like &#8220;big&#8221;, &#8220;small&#8221;, &#8220;beautiful&#8221;, and gradeable adjectives in general are vague: there is no universal (applicable in every situation) criterion for the applicability of these terms to objects, people, and so on: I&#8217;m tall compared to a pigmey, but certainly not compared to Michael Jordan. Gallup says &#8220;terrorism&#8221; for example, which is a vague term (even if it&#8217;s clearly not a gradeable adjective) &#8211; it is vague because there is no single precise criterion that tells us if some act is an act of terrorism: what terrorism is simply &#8220;depends&#8221; on whom you ask.</p>
<p>Another important reason why exact reference is difficult to accomplish is that it depends on the <em>context</em>, a broad term itself. When someone says that &#8220;our contexts are different&#8221;, it may mean something like &#8220;we know different things&#8221;, or &#8220;we are in different situations&#8221;. I&#8217;ll write more  on this in a later post. The point is that differences in context can result in different interpretations of the same survey question.</p>
<p>All of the above is, or should be well known by people who produce the kinds of surveys that Gallup does. Since it is not for precise results that they make them, the other use is as advertising for Gallup. It is also very useful for the media, because it is a starting point for discussions on why/how/when/etc. of the public&#8217;s fears. Never forget that a journalist has to make a living, that life&#8217;s hard anyway, and that Gallup here gives good material to fill many hours of TV time and newspaper space. One should simply not take this seriously.</p>
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		<title>Stock price manipulation in the 1920s</title>
		<link>http://jureta.net/stock-price-manipulation-in-the-1920s/</link>
		<comments>http://jureta.net/stock-price-manipulation-in-the-1920s/#comments</comments>
		<pubDate>Mon, 07 Jun 2010 07:28:05 +0000</pubDate>
		<dc:creator>ivanjureta</dc:creator>
				<category><![CDATA[All]]></category>

		<guid isPermaLink="false">http://jureta.net/?p=181</guid>
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What? A stock broker manipulates the stock price and makes a profit through transactions which have nothing to do with the value of the company whose stock is involved, the economy and/or industry in which the company operates.
How? By pooling money for the purchase of stocks, the broker can manage a larger amount of money [...]]]></description>
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<li><strong>What?</strong> A stock broker manipulates the stock price and makes a profit through transactions which have nothing to do with the value of the company whose stock is involved, the economy and/or industry in which the company operates.</li>
<li><strong>How?</strong> By pooling money for the purchase of stocks, the broker can manage a larger amount of money a single investor could. Any purchase he makes with more money has more impact on the stock price than if he had less money to work with. By carefully making transactions between the members of the pool, the broker can affect the expectations (that the price will rise or fall) in the eyes of the inverstors (suckers?) who are not in the pool.</li>
<li><strong>Why is this a problem?</strong><br/>Too many reasons to list. Among others, the story told usually in academia to students about the market is that it somehow works miracles in redistributing capital efficiently and does so in an impartial way. It is necessary to redistribute capital properly, yet this sort of thing was then not illegal. I don&#8217;t know if it&#8217;s prohibited today.</li>
<li><strong>Takeaway:</strong> It is completely unclear what precisely a stock price and its movements reflect. Any attempt at interpretation without considering manipulations is hopelessly naive.</li>
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<div>Sources:</div>
<ol>
<li><a href="http://books.google.com/books?id=KzrlCD2d8NwC&#038;lpg=PP1&#038;dq=Once%20in%20Golconda&#038;pg=PP1#v=onepage&#038;q&#038;f=false" target="new">John Brooks&#8217; <em>Once in Golconda: a true drama of Wall Street, 1920-1938</em></a></li>
<li>Quote found at the <a href="http://www.nakedcapitalism.com/2010/06/has-much-changed-on-wall-street-since-the-roaring-and-ripoffsky-twenties.html" target="new">nakedcapitalism</a> blog.</li>
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When you get the impression that the stock market numbers give you meaningful information to pick out what to buy, think again, please.</p>
<p>From <a href="http://books.google.com/books?id=KzrlCD2d8NwC&#038;lpg=PP1&#038;dq=Once%20in%20Golconda&#038;pg=PP1#v=onepage&#038;q&#038;f=false" target="new">John Brooks&#8217; <em>Once in Golconda: a true drama of Wall Street, 1920-1938</em></a>:</p>
<blockquote><p>The chief instrumentality through which the Wall Street insiders, with Stock Exchange approval, sheared the gullible public lambs was the stock pool…..The point of a pool manipulation was simplicity itself: it was a way of inducing the Stock Exchange ticker tape to tell a story that was essentially false, and thus to deceive the public. Then as now, the stock ticker tape….printed no news or comment – only the price and volume, along with the letters identifying the particular stock, of each transaction as it occurred&#8230;.”The tape doesn’t lie” was the sucker’s folk wisdom, but the tape could be made to lie. Even though it continued to record each transaction as faithfully and impartially as ever, the nature of those transactions themselves could be so arranged, by the people doing the transaction, as to make the watcher of the tape, in his innocence and greed, buy a gold brick.<br />
<br/><br />
The group of capitalists pooling their resources would first pick out a stock suitable for their purpose because it had glamour appeal to the public, and because there were comparatively few shares on the market, making for ease of manipulation. They would then accumulate a large block of shares&#8230;They would, if possible, make an ally if not an actual partner of the stock’s specialist on the Exchange floor&#8230;it was he who, holing in his had the supposedly secret book listing all outstanding orders to by or sell stock, had access, in Flynn’s metaphor, to the cards of all the players. Finally, they would hire their key man, an expert in manipulation called a pool manager&#8230;<br />
<br/><br />
On behalf of the pool, the pool manager, as broker, would begin buying and selling shares of the stock at frequent intervals, in no apparent pattern. Often he would buy and sell it back and forth among the members of the pool&#8230;these essentially spurious transactions, accomplished with the sympathetic help of the specialist, would be so weighted that the price of the stock would begin to rise slightly. In speculators’ jargon, it would be “active and higher”&#8230;Thus the stock would be called to the public’s attention, and the notion of making a quick profit in it planted in the public’s mind. The eager tape-watchers would gradually begin to buy – cautiously and tentatively at first, then as the activity continued to increase and the price to rise, more and more boldly. Now the pool manager’s operations would become more delicate. On some days he would abruptly switch to the selling side, simply to create confusion; then just when the public was about to decide the picnic was over, he would come back in with a torrent of buying that would sweep all along with him. Finally, in a skillfully conducted manipulation, the thing would become self-sustaining; the public would in effect take the operation over, and in a frenzy of buying at higher and higher prices would push the stock on up and up with no help from the pool manager at all. That was the moment of the final phase&#8230;often spoken of indelicately as &#8220;pulling the plug.&#8221; With a mousiness in sharp contrast to the elaborate fanfare with which he had begun his buying, the pool manager would begin feeding stock back into the market. The price would respond by turning downward, gradually at first, then more rapidly as the pool manager’s trickle of sales mounted to a flood; and before the public could collect its senses, the retreat would have become a rout, the pool wold have unloaded its entire bundle profitably, and the public would be left holding the suddenly deflated stock&#8230;<br />
<br/><br />
Pool managers with some justification thought of themselves as artists&#8230;just as the best con men disdained to use violence, so the best pool manipulators disdained these artistically inelegant practices [of planting rumors or arranging for favorable research to be published]. Their medium was the tape; they took pride in their skill to make it and it alone create precisely the effect upon the public they wanted&#8230;<br />
<br/><br />
To repeat, for practical purposes, there was nothing illegal about the pools.
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<p>Keep in mind that poker quote: If you don&#8217;t know who the sucker at the table is, it&#8217;s you.
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