ALOGIT

ALOGIT – Software for Advanced and Professional Modeling

 

Capabilities

 ALOGIT has been in intensive use by leading-edge modellers for more than 30 years and has been developed throughout that period to meet the needs of advanced modelling.  As a result, ALOGIT has a high level of reliability and numerous features and facilities that are useful for professional modelling.  

ALOGIT estimates the parameters of generalised logit models.  The main generalisations are

- tree (nested, hierarchical) models allowing the alternatives in the model to be related in less retrained ways than in simple logit models but still retaining ease of use and speed of operation;

- mixed logit models, implemented using the flexible ‘error components’ specification, which works with either linear or  the exponentiated form, which allows, for instance log-normal disturbances in the coefficients.

Mixed logit models are possible only with the EC variant of the software.

 

ALOGIT performs four key functions.

 

Data input:

 - revealed preference or stated preference, disaggregate or aggregate data can be used; choice, ranking or proportional split data can be employed;

 - input data can be manipulated and transformed freely to allow the user freedom in finding the required explanation of behaviour; extensive testing of input data to reveal modelling problems; simple controls, yet giving access when required to full sophistication;

- multiple data sets of different formats are accepted, either in succession or linked using named (key) variables; some binary matrix formats are supported.

 

Model estimation:

- all coefficients are estimated simultaneously using maximum likelihood estimation (i.e. ‘full information’ estimates);

-  models can be binomial, multinomial, or tree (nested) logit models, with unlimited branches and levels; alternatively, mixed logit or error component analysis, including differing distributions (including exponentials, e.g. lognormal) and correlated error terms;

- non-linear utility functions allow attraction variables to be included correctly;

- composite alternatives can be indicated as chosen;

- surplus measures and several detailed tests are all standard, with informative, clearly labelled, well-laid-out output, suitable for immediate incorporation in reports;

- a function in the ALOGIT Shell can be used to make comparisons between different model variants;

- an option for initial linear estimation reduces run time for complex models;

- problem sizes are not limited by ALOGIT.

 

Forecasting:

- the user can specify detailed scenarios which incorporate a series of changes in the variables influencing choice, and ALOGIT can predict, display and analyse the consequent changes in behaviour;

- a function in the ALOGIT Shell can be used to make graphical and tabular presentations of scenario outputs; alternatively, output can be made to other programs such as Excel.

 

Data processing:

- ALOGIT can be used for a range of simple data processing tasks, using the control language and statistical reporting procedures to give an efficient working environment;

- in particular, files can be output in very flexible ways (e.g. reformatted, respecified, sorted) for processing by other software.

 

All of these functions are controlled by ALOGIT’s intuitive control file, with

- a very flexible command language, including named variables, intuitively appealing definition structure for hierarchical models, named Boolean operators (TRUE, FALSE, AVAIL etc.);

- include file option for use of external files with command lines or coefficients, streamlining model (estimation) management;

- array definition of alternatives, system data items and variables;

- random number generator (using uniform, normal, logistic distributions or assignment of multinomial variable with specific probabilities);

- ‘if ... THEN ... ELSE... END’ and ‘DO ... END’ syntax, to simplify data transformations;

- intuitive specification of tree logit models using $NEST commands.

 

Sales and ordering

ALOGIT 4.3 and 4.3EC are sold on a site and time limited licence, with an initial minimum licence of six months.  Licences are available at varying lengths, and can be renewed after a lapse without additional costs above the monthly rate.  All licences become perpetual after 36 months of active life.  The perpetual licence price includes a small discount on the 36 months.  Additional licences within the same company/institute or on the same site are available at 30% of the full price.

 

 

Conditions for Acceptance of ALOGIT

ALOGIT is provided under the following conditions, which form part of the contract of sale. In accepting the program, the purchaser agrees to be bound by these conditions.

1.     The program is not copy-protected and the user may make copies for back-up purposes or to transfer to other media (e.g. hard disks).

2.     The single copy price of ALOGIT applies for use on a single processor at any one time.  Additional licences (or a multi-user licence) for parallel use on multiple processors within the same organisation can be purchased at 30% of the normal price for each additional licence or user. 

3.     The purchaser shall not provide copies of ALOGIT to any third party, and shall take reasonable steps to prevent acquisition of the program by third parties, other than by purchase from ALOGIT Software & Analysis Ltd..

4.     The programs are provided ‘as is’.  ALOGIT Software & Analysis Ltd. can take no responsibility for costs incurred because of any faults or other unexpected performance of the programs.  However, efforts will be made to correct faults, and ALOGIT Software & Analysis Ltd. is grateful to receive reports of errors or suggestions for improvements.  Purchasers will be supplied with corrected or improved versions of software at the discretion of ALOGIT Software & Analysis Ltd. or as provided for under maintenance and update agreements.

5.     ALOGIT Software & Analysis Ltd. will provide free of charge up to two hour's advice on the use of ALOGIT, troubleshooting etc., by e-mail.  Further advice can be provided at normal consulting rates. This help-desk does not include advice on modelling or detailed support regarding the theory of discrete choice analysis.

6.     The purchaser of a time-limited licence shall not attempt to use the program after the expiry of the licence.

 

Upgrade discounts for current users of ALOGIT 3.8: 10% discount for upgrading to 4.3.

Perpetual licence ALOGIT 4 or 4EC upgrade to similar 4.3 version: 80% discount

Perpetual licence ALOGIT 4.2 upgrade to similar 4.3 version: no charge

 

 

Shell program

ALOGIT is controlled by the Shell program, which acts as an interface between the user, Windows and the ALOGIT program itself.

 

The Shell’s main role is to edit ALOGIT control files and to run ALOGIT.  In these functions it offers all the standard Windows operations with cut-and-paste editing and its own Help system.  The Shell facilitates working with multiple models in a project.  Additionally, it has further functions...

- the capability to make Jack-knife runs to explore the impact of model specification errors;

- a coefficient comparison viewer, with a function allowing the user to examine the difference in coefficient values between models; the Shell can also calculate correct errors in coefficient differences, allowing a statistical test of whether coefficients are different, and errors in coefficient ratios, so that error in (for example) willingness to pay can be calculated

- a user friendly Windows based batch file program which can be activated from the shell, allowing the user to perform multiple ALOGIT runs;

- the integration of a reporting system, allowing the presentation of model scenario output using tables and graphs.

 

The Shell also controls the editing of ALOGIT INI files, which control the way in which ALOGIT interacts with the PC: the use of RAM, production of screen reports and the deletion of scratch files, for instance.

 

Ownership and History

The original PC version of ALOGIT was developed from a mainframe program in 1986 by Hague Consulting Group to support its own work.  HCG decided to offer the program to other users, while continuing to develop it.  When the consulting business of HCG merged with RAND Europe in 2001, ownership of ALOGIT passed into the hands of HPG Holding, but RAND Europe continued to market the software until the summer of 2005, at which point HPG Holding took marketing into its own hands. RAND and RAND Europe have had no connection with ALOGIT since 2005, other than as users.

 

Since January 2007 ALOGIT has been owned, supported and marketed by ALOGIT Software & Analysis Ltd..  However, development, support and marketing is still being provided by Andrew Daly, the author of the program. Dr. Rebecca Hamer, who provided support for ALOGIT for many years, is no longer involved from January 2016 onwards and we thank her for her excellent work.

 

 

Software for estimating and analysing generalised logit choice models

ALOGIT is professional software designed for the power user.  It deals easily and quickly with large models, with effectively no limit on problem size, offering a range of features and analysis capabilities that have been found useful over more than 30 years by leading-edge modellers. 

 

ALOGIT is very fast, often giving run times less than 10% those of comparable programs.

 

ALOGIT works under Windows 7 and later as well as some older variants  (XP, 2000, NT, 98 and 95) and has been installed at well over 200 locations around the world.

 

ALOGIT and this site are maintained by ALOGIT Software & Analysis Ltd. and the site was updated on 21 September 2017.