ymericson / cmfproperty

A R Package for Property Tax analysis

Transparency & Equity in Property Assessments

This package analyzes the accuracy of property assessments and produces graphs, tables, and reports designed for general use. This package is produced by the Center for Municipal Finance, a research institute at the Harris School of Public Policy, University of Chicago.

For a detailed guide on how to use this package check out our Get started page.

Installation

You can install the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("erhla/cmfproperty")

Basic Usage

First import cmfproperty.

library(cmfproperty)

To conduct our study, we need data where every roll is a unique property’s sale price and assessed value for a given year.

head(cmfproperty::example_data)
#>              PIN SALE_YEAR SALE_PRICE ASSESSED_VALUE
#> 1 17273100931118      2015      53000          33860
#> 2 18013090421010      2018      80000          60390
#> 3 12111190201042      2018     118000         108300
#> 4 13093160601015      2017     125500          87200
#> 5 14322110150000      2018    3705000        3670740
#> 6 27021200080000      2016     345000         267280

Then, preprocess your data with reformat_data and call make_report. The report from the example below can be found here.

df <- cmfproperty::example_data

ratios <-
  cmfproperty::reformat_data(
    df,
    sale_col = "SALE_PRICE",
    assessment_col = "ASSESSED_VALUE",
    sale_year_col = "SALE_YEAR",
  )


cmfproperty::make_report(ratios, 
                         jurisdiction_name = "Cook County, Illinois",
                         output_dir = "~/../Documents/GitHub/erhla.github.io/") 

#output_dir is the directory in which report is saved; default is working directory