Friday, March 18, 2016

How We Decide Which Features To Add


As developers of econometric software, one of the most common questions we are asked is how we decide which features to add to the next release of EViews.

There isn’t an easy way to answer this question – the process is often fluid and is different for every feature. Feature ideas generally come to us from one of the following sources:
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  • Directly from our user base, either on the EViews forum, through our technical support channels or through face to face meetings. 
  • From reading journal articles and text books to discover the latest trends in the field.
  • From visiting academic and professional conferences, such as ASSA, NABE or ISF.
  • From meetings held at our user conferences.
  • Research from our development team.

The recent release of EViews 9.5 gives us a chance to explore the process with some examples.

MIDAS

Perhaps the most anticipated feature in EViews 9.5 is MIDAS estimation, which allows estimation of regression models using data of different frequencies. MIDAS first came to our attention a few years ago during a casual conversation between our developers and one of our academic users at the Joint Statistical Meetings.

Our user suggested that EViews’ natural handling of data from different frequencies and our emphasis on time series analysis, coupled with MIDAS’ growing popularity made it a great candidate for a new feature.

Following up on that discussion, our development team began researching what would be involved in adding MIDAS to EViews. MIDAS would be the first estimation technique in EViews that inherently uses data based on different workfile pages.

While later attending the EViews co-sponsored ISF conference, we also noticed that a large part of the conference was devoted to MIDAS estimation and forecasting as well as nowcasting. By this time we were convinced that MIDAS was an obvious choice to add to EViews.


Model Interface

The model interface improvements added in EViews 9.5 came about as a result of direct feature requests made during a user conference we held in Washington DC for government sector EViews users. The government sector tends to be heavy users of the EViews model object, and many agencies such as the Federal Reserve, World Bank, IMF, EIA and United Nations attended and offered suggestions and had requests for ways we could improve an already extensive model interface.

For example, one of the agencies wanted a way to make their model available to the outside world, but also protect them so the official model could not be modified. This request brought about the model protection feature.

FIML

The introduction of variance restrictions to EViews’ FIML estimator came about following a discussion between one of our senior econometricians and a couple of text book co-authors who are writing a new text book featuring VAR/VEC estimation in EViews. Our econometrician happens to currently be working on revamping the VAR/VEC estimation engine in EViews with the view of adding a number of new features in the next few releases. One estimation technique the authors were interested in writing about was not currently easy to complete without variance restrictions on FIML estimation, and since our econometrician was currently interested in that area, it was quickly added.

Group Preview

The Object Preview window was added to EViews 9 as a method for quickly viewing each object in your workfile. On release, EViews 9 displayed fairly sparse information for group objects, merely listing the names of the series contained in the group.

Extending the preview window for groups was always something we planned on implementing after our EViews 9 release, but it was following a discussion between one of our developers and a large client in the financial sector that we decided to implement it as soon as EViews 9.5. This particular client utilizes EViews to quickly view graphs of multiple series. Although EViews’ multi-graph tools, in particular the multi-graph slide show, make this task easy, we thought that adding a graphical view of the underlying series to the group preview window would improve their workflow even more.

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