Why Use Instrumental Variables? e Instrumental Variables(IV)estimation is used when your model has endogenous xs That is, whenever Cov(x,l)≠0 Thus. i can be used to address the problem of omitted variable bias 2 Additionally iv can be used to solve the classic errors-in-variables problem Economics 20- Prof anderson

A True panel vs a Pooled cross section Often loosely use the term panel data to refer to any data set that has both a cross sectional dimension and a time-series dimension More precisely it's only data following the same cross-section units over time Otherwise it's a pooled cross-section Economics 20- Prof anderson

Functional form e We' ve seen that a linear regression can really fit nonlinear relationships 2 Can use logs on RHS, LHS or both Can use quadratic forms ofx's Can use interactions ofx's e How do we know if we've gotten the right functional form for our model? Economics 20- Prof anderson

Redefining variables Changing the scale of the y variable will lead to a corresponding change in the scale of the coefficients and standard errors. so no change in the significance or interpretation Changing the scale of one x variable will lead to a change in the scale of that coefficient and standard error, so no change in the significance or interpretation Economics 20- Prof anderson

Assumptions of the classical Linear Model (Clm) e So far, we know that given the Gauss Markov assumptions, OLS IS BLUE e In order to do classical hypothesis testing we need to add another assumption(beyond the Gauss-Markov assumptions) Assume that u is independent of x,x2…,xk and u is normally distributed with zero mean and variance 0: u- Normal(0, 02) Economics 20- Prof anderson

1. Producer Theory 1. Technology yi =input of good i, y =output of good i, i= yi-yi=net output, y yn) is a production plan Production possibility set Y=technologically feasible production plans yE Rn) y E Y is technologically efficient if there is no yE Y s.t. y>y

第一章 导言 一、什么是西方经济学？ 二、西方经济学的两大内容 三、西方经济学的两大方法 第二章 需求、供给、价格 Demand，Supply & Equilibrium Price 一、需求理论（消费者行为） 二、供给理论（生产者行为） 三、均衡价格（市场） 四、价格机制与价格政策 （价格的有效性与局限性） 第三章 弹性理论 The Theory of Elasticity ◼一、需求价格弹性 ◼二、弹性理论的运用 ◼三、需求的收入弹性 ◼四、需求的交叉弹性

厂商均衡: 不同市场上的厂商决定自己的产量和价格的问题

第二章 (1)列出方程组。解得P=6,Q=20。 微观经济学复习思考题ch2-1-1 (2)列出方程组。解得P=7,Q=15 2025 微观经济学复习思考题ch2-1-2