In my last post, I compiled and cleaned publicly available data on over 4.5 million stops over the past 11 years. I also presented preliminary summary statistics showing that blacks had been consistently stopped 3-6 times more than whites over the last decade in NYC. Since the last post, I managed to clean and reformat the … Continue reading Stop and Frisk: Spatial Analysis of Racial Differences
The NYPD provides publicly available data on stop and frisks with data dictionaries, located here. The data, ranging from 2003 to 2014, contains information on over 4.5 million stops. Several variables such as the age, sex, and race of the person stopped are included. I wrote some R code to clean and compile the data … Continue reading Stop and Frisk: Blacks stopped 3-6 times more than Whites over 10 years
Introduction The topic in this post is endogeneity, which can severely bias regression estimates. I will specifically simulate endogeneity caused by an omitted variable. In future posts in this series, I'll simulate other specification issues such as heteroskedasticity, multicollinearity, and collider bias. The Data-Generating Process Consider the data-generating process (DGP) of some outcome variable $latex Y $: … Continue reading Simulating Endogeneity
I used Shiny to make an interactive cobb-douglass production surface in R. It reacts to user's share of labor and capital inputs and allows the user to rotate the surface. The contour plot (isoquants) is also dynamic. Shiny works using two R codes stored in the same folder. One R code works on the user interface (UI) … Continue reading Interactive Cobb-Douglas Web App with R
Excel Spreadsheet: OkunsLaw Relative to previous recoveries, our recovery has seen decelerating unemployment without a corresponding acceleration in GDP. At each level of quarterly unemployment decrease, there is a lower than average quarterly increase in GDP.
I used excel to construct a visualization of the Cobb-Douglas production function (explicitly presented in the graph titles). The production function expresses the output of any given firm as a function of two inputs (labor and capital) and parameters (alpha and beta). When the sum of alpha and beta equals 1, it can be shown … Continue reading Cobb-Douglas Visualisation – I
The necessary and sufficient condition for convergence is that the slope of the supply curve be greater than the absolute value of the slope of the demand curve. If the slope of the supple curve is less, then price and quantity diverge from equilibrium over time.