distributions

Filename: distributions.py

Probability distributions useful in economics.

References

http://en.wikipedia.org/wiki/Beta-binomial_distribution

class quantecon.distributions.BetaBinomial(n, a, b)[source]

Bases: object

The Beta-Binomial distribution

Parameters:

n : scalar(int)

First parameter to the Beta-binomial distribution

a : scalar(float)

Second parameter to the Beta-binomial distribution

b : scalar(float)

Third parameter to the Beta-binomial distribution

Attributes

n, a, b (see Parameters)

Methods

pdf() Generate the vector of probabilities for the Beta-binomial (n, a, b) distribution.
mean
pdf()[source]

Generate the vector of probabilities for the Beta-binomial (n, a, b) distribution.

The Beta-binomial distribution takes the form

\[p(k \,|\, n, a, b) = {n \choose k} \frac{B(k + a, n - k + b)}{B(a, b)}, \qquad k = 0, \ldots, n,\]

where \(B\) is the beta function.

Parameters:

n : scalar(int)

First parameter to the Beta-binomial distribution

a : scalar(float)

Second parameter to the Beta-binomial distribution

b : scalar(float)

Third parameter to the Beta-binomial distribution

Returns:

probs: array_like(float)

Vector of probabilities over k

skew

skewness

std

standard deviation

var

Variance