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IAE 465,IAE365
MSc. Ana Moraga PumarinoDepto. Administración y Economía
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ASISTENCIA PARTICIPACION EN CLASESCONSULTASEVALUACIONESAPOYO INGLÉSGANAS DE APRENDER
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Evaluación 1: Martes 21 de abril (20%) Evaluación 2: Martes 26 de mayo (25%) Evaluación 3: Miércoles 1 de julio ( 35%) Evaluaciones parciales: Se borra solo una y no tiene derecho a
justificación
Test de lectura (se avisaran con dos semanas de anticipación)
Casos prácticos ( se entregarán en clases) Tareas (se entregarán en clases)
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Econometrics: Introduction
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Econometrics is a set of research tools employed in the business disciplines of accounting, finance, marketing and management. It is also used by social scientists, specifically researchers in history, political science and sociology. Econometrics plays an important role in such diverse fields as forestry, and in agricultural economics.
Studying econometrics fills a gap between being “a student of economics” and being “a practicing economist.”
By taking this econometrics`s course you will gain an overview of what econometrics is about, and develop some “intuition” about how things work.
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The supply of an agricultural commodity such as beef might be written as
qs is the quantity supplied, p is the price of beef, pc is the price of competitive products in production, and pf is the price of factors or inputs (for example, the price of corn) used in the production process.
( , , )s c fq f p p p
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A question facing Central Bank`s President is “How much should we increase the discount rate to slow inflation, and yet maintain a stable and growing economy?” The answer will depend on the responsiveness of firms and individuals to increases in the interest rates and to the effects of reduced investment on Gross National Product. The key elasticities and multipliers are called parameters. The values of economic parameters are unknown and must be estimated using a sample of economic data when formulating economic policies. •Poverty questions•Finance questions•Family Income and Participation in University Education
THEN….
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1. To decide how much advertising space to purchase in the local newspaper in order to increase sales.
2. To decide how much of your savings will go into a stock fund and how much into the money market.
3. To know if the median starting salary for new law school graduates is explained by the rank of the law school
DO YOU HAVE OTHER EXAMPLES?
b. Econometrics is about how to best estimate economic parameters given the data we have.
“Good” econometrics is important, since errors in the estimates used by policy makers such as the
Central Bank may lead to interest rate corrections that are too large or too small, which has
consequences for all of us.
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a. Econometrics is about how we can use economics, business or social science theory and data, along with tools
from statistics, to answer “how much” type questions.
Elija uno de los siguientes temas u otro que ud. sugiera y responda:Temas:A. PobrezaB. FelicidadC. Rendimiento académicoD. SalarioE. Otro:……………………………………….Preguntas: ¿Cuál es la pregunta que desea responder a través de un modelo ¿Qué dice la teoría respecto de los factores que explican la variable
dependiente? ¿Cuál sería un ejemplo de hipótesis en función de la pregunta que
quiere responder? ¿Qué variables cree ud. debe incluir en el modelo (una a tres) y de
qué tipo son estas variables? Describa cada variable. Donde buscaría la data para realizar este estudio.
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¿Qué relación existe entre el desempleo y la delincuencia?
Veamos gráficamente…
¿Hay relación?
tota
l num
ber i
ndex
crim
es
unemployment rate2.4 20.3
4124
164452
Estimemos el modelo…. reg crmrte d87 unem, robust Regression with robust standard errors Number of obs = 92 F( 2, 89) = 0.63 Prob > F = 0.5336 R-squared = 0.0122 Root MSE = 29.992 ------------------------------------------------------------------------------ | Robust crmrte | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- d87 | 7.940416 7.106315 1.12 0.267 -6.17968 22.06051 unem | .4265473 .9935541 0.43 0.669 -1.547623 2.400718 _cons | 93.42025 10.45796 8.93 0.000 72.64051 114.2 ------------------------------------------------------------------------------
Crimen 'unem' esta en porcentajes. 'crmrte' esta
en unidades por cada mil. Por lo tanto, si 'unem' afecta .43 veces 'crmrte' significa...
... un incremento de 1 por ciento en la tasa de desempleo esta asociado a poco menos de 1/2 aumento de crímenes por cada mil personas. Lo que es equivalente a…un aumento de un punto porcentual en el desempleo genera un crimen adicional cada dos mil personas
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1. It all starts with a problem or question2. Economic theory gives us a way of thinking about the problem3. The working economic model leads to an econometric model. 4. Sample data are obtained, and a desirable method of statistical analysis chosen, based on our initial assumptions, and our understanding of how the data were collected.5. Estimates of the unknown parameters are obtained with the help of a statistical software package, predictions are made and hypothesis tests are performed. 6. Model diagnostics are performed to check the validity of assumptions we’ve made. 7. The economic consequences and the implications of the empirical results are analyzed and evaluated. What remaining questions might be answered with further study or new and better data?
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Estimación del Modelo
EconométricoPrueba de Hipótesis
Pronóstico o predicción
Uso del ModeloControl o Política
Teoría Económica
Modelo Matemáticode la Teoría
Modeloeconométrico de la Teoría
Datos
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Introducción a la Econometría, Jeffrey Wooldridge1.Capítulos 1 y 2
Paper: Salarios por Carrera en Chile
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time series form—data collected over discrete intervals of time;
cross section form—data collected over sample units in a particular time period;
Panel data form—data that follow individual micro-units over time ( las mismas fuentes de datos son seguidas en el tiempo)
Repeated Cross Section Data form (Pseudo panel) —form—data collected over sample units in two time periods.
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Obs
Año pviviv mtrs2
1 1990 1200 1202 1990 1230 1003 1990 1300 130..…20 2010 1500 120… 2010 1670 125
obs Pais Año Tdelinc
PIBperc
1 Chile 1990 0,15 12002 Chile 2010 0,25 15003 Argentina 1990 0.08 1800…57 Uruguay 1990 0.12 156058 Uruguay 2010 0,12 165059 Francia 1990 0,16 260060 Francia 2010 0,18 2780
Repeated Cross Section Data form (Pseudo panel) —form—data collected over sample units in two time periods.
Panel data form—data that follow individual micro-units over time ( las mismas fuentes de datos son seguidas en el tiempo)
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Experimental Data
In an ideal world, from a researcher’s point of view, an economic model would describe how we might design an experiment that could be used to obtain economic observations or sample information, that then could be used to provide insights about the unknown economic parameters. Repeating the experiment T times would create a sample of T sample observations
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2. Nonexperimental Data
Most economic data are collected for administrative rather than research purposes, often by government agencies.
Banco CentralINEBanco MundialEtc.
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These data may be collected at various levels of aggregation: micro—data collected on individual economic decision making units such as individuals, households or firms. macro—data resulting from a pooling or aggregating over individuals, households or firms at the local, state or national levels. The data collected may also represent a flow or a stock: flow—outcome measures over a period of time, such as the consumption of gasoline during the last quarter of 1999. stock—outcome measured at a particular point in time, such as the quantity of crude oil held by Chevron in its US storage tanks April 1, 1999
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The data collected may be quantitative or qualitative: quantitative—outcomes such as prices or income that may be expressed as numbers or some transformation of them, such as real prices or per capita income. qualitative—outcomes that are of an “either-or” situation. For example, a consumer either did or did not make a purchase of a particular good, or a person either is or is not married.
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The phrase statistical inference will appear often in this course. We want to “infer” or learn something about the real world by analyzing a sample of data. The ways in which statistical inference are out carried include: Estimating economic parameters, such as elasticities, using econometric methods. Predicting economic outcomes, such as the enrollment in Universities for the next 10 years. Testing economic hypotheses, such as the question of whether newspaper advertising is better than store displays for increasing sales.