Slides

Tue, 05 Feb 2019 00:00:00 +0000

Create slides in Markdown with Wowchemy

Wowchemy | Documentation

Features

Efficiently write slides in Markdown
3-in-1: Create, Present, and Publish your slides
Supports speaker notes
Mobile friendly slides

Controls

Next: Right Arrow or Space
Previous: Left Arrow
Start: Home
Finish: End
Overview: Esc
Speaker notes: S
Fullscreen: F
Zoom: Alt + Click
PDF Export: E

Code Highlighting

Inline code: variable

Code block:

porridge = "blueberry"
if porridge == "blueberry":
 print("Eating...")

Math

In-line math: $x + y = z$

Block math:

$$ f\left( x \right) = ;\frac{{2\left( {x + 4} \right)\left( {x - 4} \right)}}{{\left( {x + 4} \right)\left( {x + 1} \right)}} $$

Fragments

Make content appear incrementally

{{% fragment %}} One {{% /fragment %}}
{{% fragment %}} **Two** {{% /fragment %}}
{{% fragment %}} Three {{% /fragment %}}

Press Space to play!

One Two Three

A fragment can accept two optional parameters:

class: use a custom style (requires definition in custom CSS)
weight: sets the order in which a fragment appears

Speaker Notes

Add speaker notes to your presentation

{{% speaker_note %}}
- Only the speaker can read these notes
- Press `S` key to view
{{% /speaker_note %}}

Press the S key to view the speaker notes!

Themes

black: Black background, white text, blue links (default)
white: White background, black text, blue links
league: Gray background, white text, blue links
beige: Beige background, dark text, brown links
sky: Blue background, thin dark text, blue links

night: Black background, thick white text, orange links
serif: Cappuccino background, gray text, brown links
simple: White background, black text, blue links
solarized: Cream-colored background, dark green text, blue links

Custom Slide

Customize the slide style and background

{{< slide background-image="/media/boards.jpg" >}}
{{< slide background-color="#0000FF" >}}
{{< slide class="my-style" >}}

Custom CSS Example

Let’s make headers navy colored.

Create assets/css/reveal_custom.css with:

.reveal section h1,
.reveal section h2,
.reveal section h3 {
 color: navy;
}

Questions?

Ask

Documentation

UEA Discussion

Tue, 05 Feb 2019 00:00:00 +0000

Do Appraiser and Borrower Race Affect Valuation?

Authors: Brent W. Ambrose, James N. Conklin, N. Edward Coulson, Moussa Diop, and Luis A. Lopez
Discussant: Florian Oswald

Intro

Property appraisers are trained to asses property values.
Large body of evidence going back to the 60s of discriminatory practices in mortgage markets - HMDA.
Extremely relevant setting: In remortgaging setting, appraiser is the single agent determining the value of property (not market interactions) - Appraiser faces no competition.
This Paper: Is there racial bias in remortgaging appraisals?

Approach

Use property level data on remortgage appraisals, where owner’s race is observed.
Infer the appraiser’s race from first and last name.
Compare appraisal to output of an industry model (Automatic Valuation Model, AVM).
Assess and interpret differences.

Contribution

Novel dataset and insights in a contentious area of debate.
First paper to be able to assess impact of appraiser’s race.
Found effect does not disappear with race of appraiser.

Comment 1: The AVM Model

It would be good to know more about this black box model.
We should know what variables it uses, at which geographic scale.
How well does it perform?
Outcome $Y_i$ is difference between appraiser and some estimate we don’t know much about. (We know it’s a moving target.)

🤔 Why do lenders send appraisers instead of relying on the model?

Comment 2: Unobserved Quality

$$Y_i = \delta_1 A_i + \delta_2 B_i + \delta_3 H_i + X_i \beta + \xi_i +\lambda_i +\omega_i + \epsilon_i$$

$X$: property type, investment properties, multi-unit properties, condominiums, and PUDs

Unobserved House Quality is potentially a big issue here.
Omitted variable bias could be severe. Notice that the appraiser FE does not deal with this.
If avg unobserved quality of group $g$ is relatively high, we will underestimate discrimination, and vice versa.

Here are a few candidates:

Potentially Omitted Variables

Age of property. It may be that certain groups can afford only buildings of older vintage, which could imply a lower assessment.

Investments in structure, maintainance and upkeep: Less affluent groups may find it harder to make timely investments (roof, heating, insulation…), which in turn impact the appraisal.

Investments in home improvement: Less affluent groups may find it harder to install winter garden or swimming pools, with the same effect on valuations.

Potential Solutions

A building-level fixed effect. Vladimir Avetian can use one in documenting (overt) discrimination in Moscow’s housing market. Probably hard here - unless you have a bunch of properties in a single unit?
Get more data on the property to increase $X$? With current data seemingly impossible. What about ZTRAX, which has tons of characteristics (and First and Last name of Buyer and Seller), or something similar?
More info on borrowers? Controlling for income (wealth better) would be ideal - education?

Conclusion

Very important topic.
Exciting database with appraisers race marker.
Getting better measures of quality and/or borrower characteristics would help.

Thanks!