Change default start_year to 2018

[hdoupe]

Should the default start_year be changed to 2018?

cc @martinholmer @MattHJensen

[MattHJensen]

I would recommend leaving it at 2017 until tax-calculator updates to the IRS-published 2018 parameter values that conform to the IRS rounding rules.

[martinholmer]

@hdoupe, Will the TCJA reforms work in the TaxBrain GUI with a start year of 2018?
Don't all those reforms have a provision (the cpi_offset parameter) that is implemented in 2017?

[MattHJensen]

@martinholmer asked:

Will the TCJA reforms work in the TaxBrain GUI with a start year of 2018?
Don't all those reforms have a provision (the cpi_offset parameter) that is implemented in 2017?

I believe that this feature will solve this issue:

You may specify a parameter change in the year before the Start Year with the < operator. For example, if you set the Start Year as 2018 and a Parameter Indexing Offset parameter to <,-0.0025,-0.001 then this sets the Offset to -0.0025 in 2017 and -0.001 in 2018.

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I would recommend leaving it at 2017 until tax-calculator updates to the IRS-published 2018 parameter values that conform to the IRS rounding rules.

This is still my recommendation. The relevant Tax-Calculator issue is PSLmodels/Tax-Calculator#1694 (comment)

[hdoupe]

@MattHJensen thanks for the update on the start year. Please let me know when you are ready to change it to 2018.

[hdoupe]

Also, the < operator resolves the issue with the cpi_offset parameter. See #790

[MaxGhenis]

Can this happen? I think users are no longer expecting to compare against pre-TCJA law...