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On p. 34 of his PRNN Brian Ripley comments that "The AIC was named by Akaike (1974) as 'An Information Criterion' although it seems commonly believed that the A stands for Akaike". Indeed, when introducing the AIC statistic, Akaike (1974, p.719) explains that

IC stands for information criterion and A is added so that similar statistics, BIC, DIC etc may follow.

Considering this quotation as a prediction made in 1974, it is interesting to note that in just four years two types of the BIC statistic (Bayesian IC) were proposed by Akaike (1977, 1978) and Schwarz (1978). It took Spiegelhalter et al. (2002) much longer to come up with DIC (Deviance IC). While the appearance of the CIC criterion was not predicted by Akaike (1974), it would be naive to believe that it was never contemplated. It was proposed by Carlos C. Rodriguez in 2005. (Note that R. Tibshirani and K. Knight's CIC (Covariance Inflation Criterion) is a different thing.)

I knew that EIC (Empirical IC) was proposed by people of Monash University in around 2003. I've just discovered the Focused Information Criterion (FIC). Some books refer to Hannan and Quinn IC as HIC, see e.g. this one). I know there should be GIC (Generalised IC) and I've just discovered the Information Investing Criterion (IIC). There is NIC, TIC and more.

I think I could possibly cover the rest of the alphabet, so I am not asking where the sequence AIC,BIC,CIC,DIC,EIC,FIC,GIC,HIC,IIC,... stops, or what letters of the alphabet have not been used or been used at least twice (e.g. the E in EIC can stand for either Extended or Empirical). My question is simpler and I hope more practically useful. Can I use those statistics interchangeably, ignoring the specific assumptions they were derived under, the specific situations they were meant to be applicable in, and so on?

This question is partly motivated by Burnham & Anderson (2001) writing that:

... the comparison of AIC and BIC model selection ought to be based on their performance properties such as mean square error for parameter estimation (includes prediction) and confidence interval coverage: tapering effects or not, goodness-of-fit issues, derivation of theory is irrelevant as it can be frequentist or Bayes.

Chapter 7 of Hyndman et al.'s monograph on exponential smoothing appears to follow the B-A advice when looking into how well the five alternative ICs (AIC, BIC, AICc, HQIC, LEIC) perform in selecting the model that forecasts best (as measured by a newly proposed error measure called MASE) to conclude that the AIC was a better alternative more often. (The HQIC was reported as the best model selector just once.)

I am not sure what is the useful purpose of the research exercises that implicitly treat all ICc as though they were derived to answer one and the same question under equivalent sets of assumptions. In particular, I am not sure how it is useful to investigate the predictive performance of the consistent criterion for determining the order of an autoregression (that Hannan and Quinn derived for ergodic stationary sequences) by using it in the context of the non-stationary exponentially smoothing models described and analysed in the monograph by Hyndman et al. Am I missing something here?

References:

Akaike, H. (1974), A new look at the statistical model identification, IEEE Transactions on Automatic Control 19(6), 716-723.

Akaike, H. (1977), On entropy maximization principle, in P. R. Krishnaiah, ed., Applications of statistics, Vol. 27, Amsterdam: North Holland, pp. 27-41.

Akaike, H. (1978), A Bayesian analysis of the minimum AIC procedure, Annals of the Institute of Statistical Mathematics 30(1), 9-14.

Burnham, K. P. & Anderson, D. R. (2001) Kullback–Leibler information as a basis for strong inference in ecological studies, Wildlife Research 28, 111-119

Hyndman, R. J., Koehler, A. B., Ord, J. K. & Snyder, R. D. Forecasting with exponential smoothing: the state space approach. New York: Springer, 2008

Ripley, B.D. Pattern Recognition and Neural Networks. Cambridge: Cambridge University Press, 1996

Schwarz, G. (1978), Estimating the dimension of a model, Annals of Statistics 6(2), 461-464.

Spiegelhalter, D. J., Best, N. G., Carlin, B. P. and van der Linde, A. (2002), Bayesian measures of model complexity and t (with discussion), Journal of the Royal Statistical Society. Series B (Statistical Methodology) 64(4), 583-639.

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    $\begingroup$ In conversation with Findley and Parzen (projecteuclid.org/download/pdf_1/euclid.ss/1177010133) Akaike revealed that AIC was used by an assistant in her FORTRAN program. Variable names such as IC by default implied integer quantities; a prefix such as A was sufficient to instruct the compiler that the quantity was real. Although not intending "Akaike" he realised that it also meant simply "an". (Incidentally, while this reference is, as it were, an antidote to one incorrect story, it perpetuates the misspelling of Mallows' as Mallow's.) $\endgroup$
    – Nick Cox
    Commented Feb 17, 2014 at 23:47
  • $\begingroup$ This question makes to think about "alphabetic experimental design": doe.soton.ac.uk/elearning/section3.6.jsp $\endgroup$ Commented Oct 28, 2015 at 10:34
  • $\begingroup$ This has resurfaced after 10 years. Possible answers, as shown here, range from very serious to very sardonic, but the search for criteria to choose from among criteria is at best puzzling. $\endgroup$
    – Nick Cox
    Commented Nov 29 at 17:44

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My understanding is that AIC, DIC, and WAIC are all estimating the same thing: the expected out-of-sample deviance associated with a model. This is also the same thing that cross-validation estimates. In Gelman et al. (2013), they say this explicitly:

A natural way to estimate out-of-sample prediction error is cross-validation (see Vehtari and Lampinen, 2002, for a Bayesian perspective), but researchers have always sought alternative mea- sures, as cross-validation requires repeated model fits and can run into trouble with sparse data. For practical reasons alone, there remains a place for simple bias corrections such as AIC (Akaike, 1973), DIC (Spiegelhalter, Best, Carlin, and van der Linde, 2002, van der Linde, 2005), and, more recently, WAIC (Watanabe, 2010), and all these can be viewed as approximations to different versions of cross-validation (Stone, 1977).

BIC estimates something different, which is related to minimum description length. Gelman et al. say:

BIC and its variants differ from the other information criteria considered here in being motivated not by an estimation of predictive fit but by the goal of approximating the marginal probability density of the data, p(y), under the model, which can be used to estimate relative posterior probabilities in a setting of discrete model comparison.

I don't know anything about the other information criteria you listed, unfortunately.

Can you use the AIC-like information criteria interchangeably? Opinions may differ, but given that AIC, DIC, WAIC, and cross-validation all estimate the same thing, then yes, they're more-or-less interchangeable. BIC is different, as noted above. I don't know about the others.

Why have more than one?

  • AIC works well when you have a maximum likelihood estimate and flat priors, but doesn't really have anything to say about other scenarios. The penalty is also too small when the number of parameters approaches the number of data points. AICc over-corrects for this, which can be good or bad depending on your perspective.

  • DIC uses a smaller penalty if parts of the model are heavily constrained by priors (e.g. in some multi-level models where variance components are estimated). This is good, since heavily constrained parameters don't really constitute a full degree of freedom. Unfortunately, the formulas usually used for DIC assume that the posterior is essentially Gaussian (i.e. that it is well-described by its mean), and so one can get strange results (e.g. negative penalties) in some situations.

  • WAIC uses the whole posterior density more effectively than DIC does, so Gelman et al. prefer it although it can be a pain to calculate in some cases.

  • Cross-validation does not rely on any particular formula, but it can be computationally prohibitive for many models.

In my view the decision about which one of the AIC-like criteria to use depends entirely on these sorts of practical issues, rather than a mathematical proof that one will do better than the other.

References:

Gelman et al. Understanding predictive information criteria for Bayesian models. Available from http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.295.3501&rep=rep1&type=pdf

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    $\begingroup$ In addition of reference Gelman et al. Understanding predictive information criteria for Bayesian models see also more recent paper Aki Vehtari, Andrew Gelman and Jonah Gabry (2016). Practical Bayesian model evaluation using leave-one-out cross-validation and WAIC. In Statistics and Computing, doi:10.1007/s11222-016-9696-4. arXiv preprint arXiv:1507.04544. arxiv.org/abs/1507.04544 This paper demonstrates also that reliable cross-validation can be computed in negligible time for many models. $\endgroup$ Commented Nov 15, 2016 at 8:49
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"Interchangeably" is too strong a word. All of them are criteria that seek to compare models and find a "best" model, but each defines "best" differently and may identify different models as "best".

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  • $\begingroup$ It is hard to improve on this as a terse but totally accurate summary. $\endgroup$
    – Nick Cox
    Commented Nov 29 at 18:22
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“Propose a referendum”. Just to vote! ;-) I liked the CAIC (Bozdogan, 1987) and BIC purely from my personal practice, because these criteria give a serious penalty for complexity, we got more parsimony, but I always displayed the list of good models - to delta 4-6-8 (instead of 2). In step of investigating parameters (because we have a “good stretching of candidate models”), the MM averaging (B&A) often almost nothing changes. I am slightly skeptical about both the classical AIC and AICc (H&T, popularized by B&A), since they often give a very "thick layer of the cream". ;-)

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The central problem with all statistical information criteria is really the central problem with statistical models in general:

They aren't dynamical models.

If one admits dynamical models (even if only implicitly*) for causal inference, one is immediately drawn to algorithmic information criteria. The gold standard algorithmic information criterion is approximating the Kolmogorov complexity of the data.

There are two bad habits in sociology that contribute to the failure to recognize this:

  1. Focusing on a single outcome variable.
  2. Failure to adopt the single-dataset multiple analyst approach to contain the worst practices of sociology.

#1 blocks one from considering dynamical models because single variable dynamical systems are practically useless.

#2 is related to #1 in that even when a single-dataset is provided to multiple analysts, it is generally within the context of predicting a single variable of interest. But if, rather than constructing a new dataset for each new analysis, the community were to curate a "single dataset" of high quality, involving many inter-related social measures, it would become apparent that dynamical models were the only way to predict not just single measures, but all measures of interest.

That this is still not recognized in sociology, despite the emergence of state space models in machine learning, is a clear indictment of its academic culture.

* Although dynamical systems are dependent on time series data, that is too-restrictive since causal inference is often if not usually attempted without explicit time series data. In causal analyses time dependence is assumed even if not imputed as a latent variable. The inferred causal processes generating the data under algorithmic information (embodied, say, in a state space model) must, of course, be explicit.

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  • $\begingroup$ This seems to assume that (1) researchers reading this (anyone other than students just starting out) have time series data (2) they are working in sociology or take best sociological practice as exemplary. The intersection of those sets is, I guess wildly, of the order of 1% of the readership here. Otherwise put, this is a rather puzzling answer. $\endgroup$
    – Nick Cox
    Commented Nov 29 at 17:39
  • $\begingroup$ When I speak of "academic culture", precedent and path dependencies matter. My recollection from the early 1970s in the Lindquist Center For Measurement was that the only statistical software in widespread use at that time was the Statistical Package for the Social Sciences. This is not to entirely discount the contribution of various FORTAN libraries in use at that time by the hard sciences, to the culture of statistical software during the many decades of explosive growth in algorithmic statistics enabled by Moore's Law. But all with nary a mention of algorithmic information. $\endgroup$ Commented Nov 29 at 18:18
  • $\begingroup$ I was active in the early 1970s and agree that SPSS was the most often mentioned package in my hearing, although I wrote Fortran programs instead. Sure, but 50 years later the landscape is quite different. $\endgroup$
    – Nick Cox
    Commented Nov 29 at 18:22
  • $\begingroup$ It would be interesting to see statistics on the application areas most often referenced in stats.stackexchange even though it may not be representative of the larger academic community and my point about path dependence and precedence contributions to academic culture are less dependent on current application areas. $\endgroup$ Commented Nov 30 at 2:51

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