讲解：Economics 123B、R、R、dataProlog|Processing

Economics 123BEconometrics II Winter 2019Homework 3Due on 2/28/2019Problems and DerivationsProblem 1: Suppose that we want to evaluate the effect of several variables onannual saving and that we have a panel data set on individuals collected in January1990 and January 1992. If we include a year dummy variable for 1992 and use firstdifferencing, can we also include age in the original model? Please explain.Problem 2: Consider a data set consisting of observations on i = 1, . . . , n unitsover t = 1, . . . , T time periods and suppose that n is large and T is small (e.g., youhave n = 5000 patients observed over T = 10 years). Write down an econometricmodel that can be used to analyze the data and explain its components. Whatproblems arise if in your regression you ignore the fact that patients are potentiallyheterogeneous? Show an example of this graphically. Discuss one approach toestimating the parameters of this model, listing the necessary steps.Problem 3: The mock dataset hw3 data.csv on the courEconomics 123B作业代做、代写R编程设计作业、R实验作业代写、代做data留学生作业 代写留学生Prologse website includes observationson i = 1, . . . , 100 California counties over t = 1, . . . , 4 time periods. Thedependent variable y, stored in column 1, is a measure of pollution. The next threecolumns include determinants of y, and a county indicator appears in column 5.1. Load the data into your favorite statistics software. Without using panel datapackages or toolboxes, implement the mean-differncing and first-differcing fixedeffects estimators. Show your code and report your point estimates. Are theestimates under mean-differencing and first-differencing comparable? (Note: toconfirm the accuracy of your code, you may wish to compare your results tothose obtained from the panel data analysis tools in your software, e.g., if usingR, install package plm and enable it with the command library(plm) at the topof your script).2. Provide a forecast of pollution if x1 = 1.1, x2 = 1.5, and x3 = .2. Because youhave removed the county specific intercepts, what is the proper interpretationof your forecast?转自：http://ass.3daixie.com/2019030113155146.html