From A Statistician Walks into a Grocery Store...
Thanks to Ramez Naam!
41 minutes ago
Comments, observations and thoughts from two left coast bloggers on applied statistics, higher education and epidemiology. Joseph is a new assistant professor. Mark is a marketing statistician and former math teacher.
One reason for this, I think, is that we fail to teach well how, with enough data, any non-zero parameter or difference becomes statistically significant at arbitrarily small levels. The proverbial expression of this, due I believe to Andy Gelman, is that "the p-value is a measure of sample size". More exactly, a p-value generally runs together the size of the parameter, how well we can estimate the parameter, and the sample size. The p-value reflects how much information the data has about the parameter, and we can think of "information" as the product of sample size and precision (in the sense of inverse variance) of estimation, say n/σ2. In some cases, this heuristic is actually exactly right, and what I just called "information" really is the Fisher information.But I found this way of talking about p-values to be extremely useful, and something that should be kept in mind in Epidemiology -- where a significant association estimates from a big sample with a small effect can often be uninteresting. You never reduce bias to zero in a real observational study and interventions rarely remove an association entirely (as not everyone changes behavior or mitigation is partial). In the era of big data, this becomes important.
Academic politics, like any other type of politics, is better served by words that are evocative and ambiguous, but if an argument is transparently political, economists interested in science will simply ignore it. The style that I am calling mathiness lets academic politics masquerade as science. Like mathematical theory, mathiness uses a mixture of words and symbols, but instead of making tight links, it leaves ample room for slippage between statements in natural versus formal language and between statements with theoretical as opposed to empirical contentBrad DeLong has had some sharp comments, but I think the best reply to Romer's critics came from Romer himself.
One thing has been bothering me for years now is not just that economists often combine overly simplistic modeling assumptions with overly complicated math (we all do that from time to time), but that many seem to equate these things with thinking scientifically.
The biggest spender in the LAUSD school board election is the California Charter Schools Association Advocates' PACs, which so far has spent $2.2 million. Their funds primarily support charter school executive Ref Rodriguez in the east Los Angeles' District 5 race and against incumbent Bennett Kayser, a charter school opponent.
"We are supportive of candidates who have got a vision of great public schools in Los Angeles, and we would like charters to be part of that solutions," said Gary Borden, executive director of CCSA Advocates.
Last year, the charter school PAC received donations from local philanthropist Eli Broad, Netflix CEO Reed Hastings and former New York City Mayor Michael Bloomberg.
The names of more recent donors aren't required to be disclosed just yet: California requires these types of PACs to publish contributors on a semi-annual basis, often falling after Election Day.
Max and Ida Caesar ran a restaurant, a 24-hour luncheonette. By waiting on tables, their son learned to mimic the patois, rhythm and accents of the diverse clientele, a technique he termed double-talk, which he used throughout his career. He first tried double-talk with a group of Italians, his head barely reaching above the table. They enjoyed it so much that they sent him over to a group of Poles to repeat his native-sounding patter in Polish, and so on with Russians, Hungarians, Frenchmen, Spaniards, Lithuanians, and Bulgarians.
Of his double-talk routines, Carl Reiner said, "His ability to doubletalk every language known to man was impeccable," and during one performance Caesar imitated four different languages but with almost no real words. Despite his apparent fluency in many languages, Caesar could actually speak only English and Yiddish. In 2008, Caesar told a USA Today reporter, "Every language has its own music ... If you listen to a language for 15 minutes, you know the rhythm and song." Having developed this mimicry skill, he could create entire monologues using gibberish in numerous languages, as he did in a skit in which he played a German general.
Thus, “the rules of equity or justice [regarding property] depend entirely on the particular state and condition in which men are placed, and owe their origin and existence to that utility, which results to the public from their strict and regular observance” (Enquiry Concerning the Principles of Morals, 3).In other words, property rights arise because they are useful and are an imposed social construct by a polity. It is a measure of how incredibly successful that the modern state has been at protecting property rights that we see property rights as an innate right.
"[T]here are lots of reasons to worry about the state of the polling industry," Silver concluded, citing a range of factors. "There may be more difficult times ahead for the polling industry." This is quite a notable statement. The former New York Times statistician gained national fame for correctly anticipating the outcome of the 2008, 2010 and 2012 U.S. elections. He did this largely by understanding how to read the polls, and by knowing which polls were worth reading. (Never mind that he wasn't the only one. In fact, in 2012, the Daily Kos blogger Markos Moulitsas was more accurate than Silver in predicting the outcome of the 2012 electoral college. Needless to say, Moulitsas was not offered a high-paying job at ESPN.) If Silver is declaring that the world has a polling problem, and that there may be more difficult times ahead for the polling industry, what is Silver's added value in an election cycle? His ability to forecast elections is largely dependent on the accuracy of polling. Without that, what is his raison d'etre -- other than to point out how bad polling caused him to make inaccurate forecasts?
On Monday night I headed to the most affordable grocery store I could think of: Trader Joe's.As mentioned before, Trader Joe's is not a bargain grocery. The target demographic might be best described as budget-conscious foodie. If you're looking for imported, organic and (most importantly) prepared food, you will find some very reasonable options.
I was super conscious of sales as I wove through TJs, and the steals of the night included: sweet potatoes ($0.49 each), bananas ($0.19 each), and a 16-ounce bag of bowtie pasta ($0.99).
There are a few reasonable choices here -- the beans, the pasta, the bananas, the sweet potatoes -- but after that it gets ugly quickly. By my calculations and based on a couple of trips to Trader Joe's for research (with the caveat that some foods are cheaper in LA), more than half of Elkins' money went to purchases that were either bad or which could be replaced by much cheaper alternatives.
Bowtie pasta ($0.99)
Can of garbanzo beans ($0.89)
Can of black beans ($0.89)
Butternut squash soup ($2.79)
Chunky peanut butter ($2.49)
8 corn tortillas ($1.99)
Half-gallon of almond milk ($2.99)
Dozen organic eggs, since the only remaining non-organic eggs were cracked ($3.99)
8-pack of maple and brown sugar oatmeal ($2.99)
7 bananas ($1.33)
Bag of spinach ($1.99)
1 yellow onion ($0.79)
3 sweet potatoes ($1.47)
Sea salt ($0.99)
One of the biggest mistakes I made was not buying butter or oil, essential cooking ingredients that I take for granted and therefore completely overlooked.
You'll also notice there is no coffee, a staple in my normal diet but one that would blow the budget.
And I’ve had an awful lot of conversations with people who think they’re being insightful when they declare that it turns out it’s really hard to get a job or to stretch a dollar. That it just can’t be done. Actually, guys, it’s hard for you to be poor. Lots of us are great at it. Lots of us do it every goddamn day.