Version Notes¶
These notes will only include major changes.
1.1¶
Covariance restrictions
Demographic-specific product availability
1.0¶
Support matching smooth functions of micro means
Optimal micro moments
Support elimination of groups of products for second choices
Micro data simulation
Micro moment tutorials
0.13¶
Overhauled micro moment API
Product-specific demographics
Passthrough calculations
Added problem results methods to simulation results
Profit Hessian computation
Checks of pricing second order conditions
Newton-based methods for computing equilibrium prices
Large speedups for supply-side and micro moment derivatives
Universal display for fixed point iteration progress
Support adjusting for simulation error in moment covariances
0.12¶
Refactored micro moment API
Custom micro moments
Properly scale micro moment covariances
Pickling support
0.11¶
Elasticities and diversion ratios with respect to mean utility
Willingness to pay calculations
0.10¶
Simplify micro moment API
Second choice or diversion micro moments
Add share clipping to make fixed point more robust
Report covariance matrix estimates in addition to Cholesky root
Approximation to the pure characteristics model
Add option to always use finite differences
0.9¶
More control over matrices of instruments
Split off fixed effect absorption into companion package PyHDFE
Scrambled Halton and Modified Latin Hypercube Sampling (MLHS) integration
Importance sampling
Quantity dependent marginal costs
Speed up various matrix construction routines
Option to do initial GMM update at starting values
Update BLP example data to better replicate original paper
Lognormal random coefficients
Removed outdated default parameter bounds
Change default objective scaling for more comparable objective values across problem sizes
Add post-estimation routines to simplify integration error comparison
0.8¶
Micro moments that match product and agent characteristic covariances
Extended use of pseudo-inverses
Added more information to error messages
More flexible simulation interface
Alternative way to simulate data with specified prices and shares
Tests of overidentifying and model restrictions
Report projected gradients and reduced Hessians
Change objective gradient scaling
Switch to a lower-triangular covariance matrix to fix a bug with off-diagonal parameters
0.7¶
Support more fixed point and optimization solvers
Hessian computation with finite differences
Simplified interface for firm changes
Construction of differentiation instruments
Add collinearity checks
Update notation and explanations
0.6¶
Optimal instrument estimation
Structured all results as classes
Additional information in progress reports
Parametric bootstrapping of post-estimation outputs
Replaced all examples in the documentation with Jupyter notebooks
Updated the instruments for the BLP example problem
Improved support for multiple equation GMM
Made concentrating out linear parameters optional
Better support for larger nesting parameters
Improved robustness to overflow
0.5¶
Estimation of nesting parameters
Performance improvements for matrix algebra and matrix construction
Support for Python 3.7
Computation of reasonable default bounds on nonlinear parameters
Additional information in progress updates
Improved error handling and documentation
Simplified multiprocessing interface
Cancelled out delta in the nonlinear contraction to improve performance
Additional example data and improvements to the example problems
Cleaned up covariance estimation
Added type annotations and overhauled the testing suite
0.4¶
Estimation of a Logit benchmark model
Support for fixing of all nonlinear parameters
More efficient two-way fixed effect absorption
Clustered standard errors
0.3¶
Patsy- and SymPy-backed R-style formula API
More informative errors and displays of information
Absorption of arbitrary fixed effects
Reduction of memory footprint
0.2¶
Improved support for longdouble precision
Custom ownership matrices
New benchmarking statistics
Supply-side gradient computation
Improved configuration for the automobile example problem
0.1¶
Initial release