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Questions tagged [statistics]

Statistics is a branch of mathematics dealing with the collection, analysis, interpretation, presentation, and organization of data. For data requests, use the [data-request] tag instead, or consider our sister site Open Data Stack Exchange.

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12 votes
3 answers
63k views

Prove the sample variance is an unbiased estimator

I have to prove that the sample variance is an unbiased estimator. What is is asked exactly is to show that following estimator of the sample variance is unbiased: $s^2=\frac{1}{n-1}\sum\limits_{i=1}^...
Andreas Dibiasi's user avatar
12 votes
2 answers
300 views

Why use empirical macroeconomic models when they are not policy invariant (Lucas Critique)?

With high probability this question is duplicate, and I tried to find one already in the community, but I was unsuccessful. According to the Lucas Critique, in its more general terms, the problem ...
An old man in the sea.'s user avatar
11 votes
6 answers
2k views

Did previous researchers fail to detect the hot hand simply because of a statistical fallacy?

Many basketball fans/players believe that having made several shots in a row, the next shot is more likely to go in. This is sometimes called the hot hand. Starting (I think) with Gilovich, Mallone, ...
user avatar
9 votes
5 answers
670 views

Lack of skilled IT workforce, but they do not raise wages

In my country, Portugal, many IT companies are always complaining in media regarding the lack of skilled IT workforce, but they do not raise wages. We have statistical data from the government that ...
daniel__'s user avatar
  • 191
7 votes
4 answers
595 views

P-value hacking

P-value hacking is the "art" of looking at different outcomes and specifications until you get a "false positive", i.e. a p value under, say, 0.05, which only noise and not true under the data ...
FooBar's user avatar
  • 10.7k
7 votes
5 answers
1k views

What is the average economic value of a human life?

What is the economic value of a human life? If there are multiple methods to use in calculating, what are they, which method is preferred, and why? Considerations/sub-questions on methods A. Is the ...
LightCC's user avatar
  • 217
7 votes
3 answers
12k views

Type - I Error & Type - II Error: Pregnancy test analogy - is it legit?

I found this picture in my stats book but I'm now confused to what 'positive' and 'negative' is referring to. As seen in the table below, Type 1 error is the error that its H0 is actually true but ...
user8491363's user avatar
7 votes
2 answers
810 views

Do circular invoices count in GDP?

I'm trying to understand GDP and what it means. Say that there are two US software companies, Foo Inc and Bar Inc. Foo Inc produces software and charges Bar \$1 million for its usage, while Bar Inc ...
Ram Rachum's user avatar
7 votes
2 answers
128 views

Do people really care about higher moments?

I have heard that people often handle uncertainty using point estimates not probability distributions. However, I have been unable to find any evidence for this in the heuristics and biases literature....
user avatar
7 votes
1 answer
102 views

Understanding this particular criticism of RCTs by Deaton and Cartwright

Deaton and Cartwright make several criticisms of randomized controlled trials (RCTs). My question is about this one in particular from a 2016 VoxEU piece: Well-conducted RCTs could provide unbiased ...
user avatar
7 votes
1 answer
152 views

Mythbusters - Determine optimal boarding strategy based on time and satisfaction score

Most airlines board passengers starting from the back of the plane and then working their way towards the front (after boarding priority classes and passengers). In an episode of Mythbusters, Adam ...
BCLC's user avatar
  • 370
7 votes
1 answer
5k views

White versus Newey-West standard errors

could you please help me to understand when I should use either white or newey-west standard erros? I do work with time-series data. I look at both contemporaneous and intertemporal realtionships. ...
frame's user avatar
  • 91
6 votes
3 answers
10k views

Robust Standard Errors in Fixed Effects Model (using Stata)

I'm trying to figure out the commands necessary to replicate the following table in Stata. This table is taken from Chapter 11, p. 357 of Econometric Analysis of Cross Section and Panel Data, Second ...
jmbejara's user avatar
  • 9,355
6 votes
2 answers
90 views

Government spending and revenue statistics

I am looking for thorough statistics of budgetary spending and revenues by category for approx all oecd countries. If not for all oecd i will be happy to have data only for Switzerland. I am ...
Krowskir's user avatar
  • 327
6 votes
2 answers
131 views

How can I get total home values on Zillow?

I am interested in getting aggregate dollar values for listings/sales on Zillow (for the whole country summed together, for example). Unfortunately, Zillow's data page seems to only show the "ZHVI", ...
Lassie Fair's user avatar
  • 1,728
6 votes
1 answer
100 views

Precision of language regarding "statistical significance" in Wooldridge's *Introductory Econometrics* (7th ed)

I've been reading Jeffrey Wooldridge's textbook Introductory Econometrics: A Modern Approach (7th edition) in preparation for a class I will be teaching. I've appreciated the precise language he uses, ...
Austin D.'s user avatar
6 votes
1 answer
1k views

Where do computational economists work

Does anybody know what kind of work or where computational economists end up working? It seems most end up in research...
cyvarza's user avatar
  • 117
5 votes
4 answers
14k views

Python vs R (vs Stata): the old battle revisited

I am an avid Python user. I know Stata but I'm not a pro. I don't know R. I do econometrics (mostly time series, but also cross-section and panel), and statistics, and Python seems quite sufficient in ...
Jay's user avatar
  • 51
5 votes
1 answer
2k views

What R-squared is a low R-squared?

I keep hearing that R-squared does not really matter in economics research and that due to the unpredictable human nature, economics research regressions tend to have low R-squared. But how much is ...
Jerry's user avatar
  • 173
5 votes
1 answer
423 views

Convergence in probability and convergence in distribution

Im a little confused about the difference of these two concepts, especially the convergence of probability. I understand that $X_{n} \overset{p}{\to} Z $ if $Pr(|X_{n} - Z|>\epsilon)=0$ for any ...
Martin 's user avatar
5 votes
2 answers
130 views

What are some helpful online tools (databases, etc..) for economic analysts?

More specifically, I'm looking for a online database of US economic statistics that is regularly updated. Most of my searches result in older data, that is not particularly useful for what I need it ...
marcbally's user avatar
5 votes
2 answers
581 views

Data mining in econometric modelling

Would I be "mining the data" in a time series analysis if I add more lags than theory suggests? For instance, for annual data analysis, it is recommended that two lags would be sufficient to capture ...
london's user avatar
  • 2,010
5 votes
1 answer
103 views

Interpreting the ratio of two variances in a Bayesian decision problem

Given a normal prior with mean $\mu_0$ and variance $\sigma_0^2$, and a normal likelihood with known variance $\sigma^2$, the Bayesian posterior, after observing $n$ iid signals $x_1,\dots,x_n$, is ...
Herr K.'s user avatar
  • 15.4k
5 votes
1 answer
676 views

Why the subjective "Owners’ equivalent rent of residences" is included in the CPI?

I was reading about the calculation of the Shelter index of the CPI which accounts to more than 30% of the entire basket. It consists mainly of two parts: (1) Rent of primary residence, and (2) Owners’...
d_e's user avatar
  • 283
5 votes
1 answer
75 views

Is there any statistics available on forecasting failures?

Like what percentage of financial/economical forecast fail? Or how often do politicians create bad policies based on wrong forecasts?
Andrew Potapov's user avatar
4 votes
1 answer
421 views

"Derivative" of an indicator function

I am studying a paper where I have the following indicator function: $\text{I}(i) = \mathbf{1} \{ \eta^* - \eta(\beta(i)) + u(i) > 0 \}$ where $\beta(i)$ is taken from uniform distribution $U[\chi-\...
Dario's user avatar
  • 85
4 votes
1 answer
826 views

Where can I find lorenz curve of countries?

I have been able to find values of Gini coefficient but have not been able to find their corresponding lorenz curves.
Soham Phargade's user avatar
4 votes
2 answers
210 views

How prevalent is the use of machine learning among economists?

I wonder how machine learning, particularly deep neural net which is considered the state-of-the-art among many data scientists, is used among economists, or other experts who is in in the similar ...
Blaszard's user avatar
  • 265
4 votes
1 answer
209 views

Deriving an equation in Banerjee "A Simple Model of Herd Behavior" (1992)

I am reading "A Simple Model of Herd Behavior" by Banerjee (1992). A short summary of the model is the following. There is a probability $\alpha$ that each person receives a signal telling ...
James_'s user avatar
  • 45
4 votes
1 answer
280 views

Have social accounting matrices and input output models fallen out of fashion? if so, why?

My perception may be uninformed but 'worldwide' I believe collection of official data on input output tables of economies dont seem to be keeping up with the times. Im aware that compilation of such ...
user3459004's user avatar
4 votes
2 answers
207 views

Pareto curve vs Pareto chart

I was searching online for some notes on how to draw a Pareto curve on income distribution. That's when I came across Pareto chart which is a bar diagram and is used in quality control. Are these the ...
Harry's user avatar
  • 139
4 votes
1 answer
257 views

Partial R2 and contribution of Regressors

I asked a similar question on Cross Validated, but got no answer. The following question is sufficiently different. Consider the following deterministic relationship:$$Y_{t}=C_{t}+I_{t}+G_{t}+(X_{t}-...
ChinG's user avatar
  • 1,633
4 votes
1 answer
123 views

Why do we use mostly two-tailed Student's t-statistics to find if an explanatory variable is significant in a regression?

Let's assume a standard regression model: $$y=\beta x+u$$ We'd like to test if an variable $x_j$ is relevant in the respect of the model. t-statistics: $$t=\frac{\hat{\beta_j}-b}{SE(\hat{\beta_j})}$$ ...
Übel Yildmar's user avatar
4 votes
3 answers
1k views

Why does adding a quadratic term to a regression change unrelated coefficients?

I'm in STATA and using 2010 data from Ipums. I'm trying to measure the wage differential between single men, married men, single women, and married women. I ran my first regression and got the ...
Limehouse Chappy's user avatar
4 votes
1 answer
94 views

Proof Mean with a Smaller Sample Size is a Mean Preserving Spread

I am attempting the following exercise from Annie Liang's excellent lecture notes: I have written an attempted proof (below), but I'm worried about the independence assumption I make. In particular, ...
matthewoulton's user avatar
4 votes
1 answer
99 views

How to deal with multiplicatively constant and additively constant fixed effects?

From Nick Huntington-Klein, The Effect: Fixed effects is a method of controlling for all variables, whether they’re observed or not, as long as they stay constant within some larger category. How can ...
Daycent's user avatar
  • 260
4 votes
1 answer
579 views

How does the companies set up utility function for its own purposes?

How does the companies set up utility function for its own purposes? In another word, what is the types statistics data that is usually consider and statistical method being used to set up these ...
Victor's user avatar
  • 743
4 votes
2 answers
215 views

Re-evaluation of Consumer Price Index (C.P.I.) weights

How are the weights of the various household items in the Consumer Price Index (C.P.I.) basket decided, i.e., how are they re-evaluated every year? Is it done manually or automatically? If its done ...
Python_user's user avatar
4 votes
1 answer
150 views

A Gamma-Weibull distribution for empirical auction model

I am reading Comparing Open and Sealed Bid Auctions: Evidence From Timber Auctions (working paper version) and struggling with getting a log likelihood function about a Gamma-Weibull distribution. In ...
hrkshr's user avatar
  • 195
4 votes
1 answer
404 views

How to interpret fixed effects?

I want to interpret the output of a fixed effects regression and need help with interpreting the country-fixed effects. The regression is the following: ...
mag123's user avatar
  • 41
4 votes
1 answer
206 views

Why N>T is required on system GMM estimations?

My question is why N>T is required when working with dynamic panel estimations based on system GMM, such as xtdpdsys at stata. Is that based on the potential lost of information due to orthogonal ...
RLF's user avatar
  • 41
4 votes
2 answers
206 views

How to approach rigorous probability theory from an economics background?

I am attempting to read around the theory of probability theory from the ground up, coming from a background of economics I have little experience in set/measure theory, whilst I am not new to ...
user avatar
4 votes
1 answer
88 views

Swanson and Williams (2014): restricting based period response to one

I would like to replicate the results as in Swanson and Williams (AER 2014): "Measuring the Effect of the Zero Lower Bound on Medium- and Longer-Term Interest Rates" https://www.aeaweb.org/...
user100525's user avatar
4 votes
1 answer
316 views

How to approximate stochastic volatility model with finite-state Markov chain?

A common practice when computing solutions to stochastic dynamic optimization problems is to approximate an exogenous forcing process $z_{t+1} = \rho z_t + \sigma \epsilon_{t+1}$ with a finite-state ...
ivansml's user avatar
  • 1,096
4 votes
3 answers
187 views

Clustered standard errors

(My research question is economics based, but for simplicity, I'm using a non-economics example) Suppose I'm trying to find out whether average body temperature of a population is equal to 37 degrees ...
wwl's user avatar
  • 193
4 votes
1 answer
4k views

What is the "gross national saving" for?

I don't understand what the term Gross National Saving is for. According to the world factbook, it represents the following: Gross national saving is derived by ...
Blaszard's user avatar
  • 265
4 votes
0 answers
81 views

Joint significance test in a difference-in-differences setting

I ran the following difference-in-differences regression in software and have some questions about the interpretation of the resulting coefficients and their (joint) significance: $$ P_{it} = \gamma_i ...
Fabian Axer's user avatar
4 votes
0 answers
206 views

Dynamic demand model in many good competitive markets and price optimization

This is a question about demand models, price optimization, dynamic pricing, big data, online learning, so I will cross-post in other communities. $\mathbf{Background}$ I am interested in dynamic ...
VictorZurkowski's user avatar
3 votes
3 answers
362 views

How to prove that Adjusted R^2 is less than R^2

The adjusted R^2 formula is : $$ \overline{R}^{2}=1-\left( \left( 1-R^{2}\right) \cdot > \dfrac{n-1}{n-k}\right) $$ In case of k > 1 , I continue like that; $$ \overline{R}^{2}=1-\left( \...
Tatanik501's user avatar
3 votes
2 answers
244 views

How to average CDFs of one variable across years

I have wealth-to-income data for 10 years. I computed the cdf of this variable in each year. Now I'm trying to average the cdfs across years. In each each, the number of observations is different. ...
Susan's user avatar
  • 31

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