Lecture 15: Effect modification, and confounding in logistic regression
|
|
- Charlene Clarke
- 6 years ago
- Views:
Transcription
1 Lecture 15: Effect modfcaton, and confoundng n logstc regresson Sandy Eckel seckel@jhsph.edu 16 May
2 Today s logstc regresson topcs Includng categorcal predctor create dummy/ndcator varables just lke for lnear regresson Comparng nested models that dffer by two or more varables for logstc regresson Ch-square (X 2 ) Test of Devance.e., lkelhood rato test analogous to the F-test for nested models n lnear regresson Effect Modfcaton and Confoundng 2
3 Example Mean SAT scores were compared for the 50 US states. The goal of the study was to compare overall SAT scores usng state-wde predctors such as per-pupl expendtures average teachers salary 3
4 Varables Outcome Total SAT score [sat_low] 1=low, 0=hgh Prmary predctor Average expendtures per pupl [expen] n thousands Contnuous, range: , mean: 5.9 Doesn t nclude 0: center at $5,000 per pupl Secondary predctor Mean teacher salary n thousands, n quartles salary1 lowest quartle salary2 2 nd quartle salary3 3 rd quartle salary4 hghest quartle four dummy varables for four categores; must exclude one category to create a reference group 4
5 Analyss Plan Assess prmary relatonshp (parent model) Add secondary predctor n separate model (extended model) Determne f secondary predctor s statstcally sgnfcant How? Use the Ch-square test of devance 5
6 Models and Results (note that only exponentated slopes are shown) p log = β + β1 1 p ( Expendture 5) 0 Model 1 (Parent): Only prmary predctor sat_low Odds Rato Std. Err. z P> z [95% Conf. Interval] expenc p log = β0 + β1( Expendture 5) + β2i ( Salary = 2) + β3i( Salary = 3) + β4i ( Salary = 1 p 4) Model 2 (Extended): Prmary Predctor and Secondary Predctor sat_low Odds Rato Std. Err. z P> z [95% Conf. Interval] expenc salary salary salary
7 The X 2 Test of Devance We want to compare the parent model to an extended model, whch dffers by the three dummy varables for the four salary quartles. The X 2 test of devance compares nested logstc regresson models We use t for nested models that dffer by two or more varables because the Wald test cannot be used n that stuaton 7
8 Performng the Ch-square test of devance for nested logstc regresson 1. Get the log lkelhood (LL) from both models Parent model: LL = Extended model: LL = Fnd the devance for both models Devance = -2(log lkelhood) Parent model: Devance = -2(-28.94) = Extended model: Devance = -2(-28.25) = Devance s analogous to resdual sums of squares (RSS) n lnear regresson; t measures the devaton stll avalable n the model A saturated model s one n whch every Y s perfectly predcted 8
9 Performng the Ch-square test of devance for nested logstc regresson, cont 3. Fnd the change n devance between the nested models = devance parent devance extended = = 1.38 = Test Statstc (X 2 ) 4. Evaluate the change n devance The change n devance s an observed Ch-square statstc df = # of varables added H 0 : all new β s are 0 n the populaton.e., H 0 : the parent model s better 9
10 The Ch-square test of devance for our nested logstc regresson example H 0 : After adjustng for per-pupl expendtures, all the slopes on salary ndcators are 0 (β 2 = β 3 = β 4 = 0 ) X 2 obs = 1.38 df = 3 Wth 3 df and α=0.05, X 2 cr s 7.81 X 2 obs < X 2 cr Fal to reject H 0 Conclude: After adjustng for per-pupl expendture, teachers salary s not a statstcally sgnfcant predctor of low SAT scores 10
11 Notes about Ch-square devance test The devance test gves us a framework n whch to add several predctors to a model smultaneously Can only handle nested models Analogous to F-test for lnear regresson Also known as "lkelhood rato test" 11
12 How can I do the Ch-square devance test n R? 1. Ft parent model ft.parent <- glm(y~x1, famly=bnomal()) 2. Ft the extended model (parent model s nested wthn the extended model) ft.extended <- glm(y~x1+x2+x3, famly=bnomal()) 3. Perform the Ch-square devance test anova(ft.parent, ft.extended, test="ch") Example output: Analyss of Devance Table Model 1: y ~ x1 Model 2: y ~ x1 + x2 + x3 Resd. Df Resd. Dev Df Devance P(> Ch ) Ch-square Test Statstc Degrees of freedom P-value 12
13 Effect Modfcaton and Confoundng n Logstc Regresson Heart Dsease Smokng and Coffee Example 13
14 Effect modfcaton n logstc regresson Just lke wth lnear regresson, we may want to allow dfferent relatonshps between the prmary predctor and outcome across levels of another covarate We can model such relatonshps by fttng nteracton terms n logstc regressons Modellng effect modfcaton wll requre dealng wth two or more covarates 14
15 Logstc models wth two covarates logt(p) = β 0 + β 1 X 1 + β 2 X 2 Then: logt(p X 1 =X 1 +1,X 2 =X 2 ) = β 0 + β 1 (X 1 +1)+ β 2 X 2 logt(p X 1 =X 1,X 2 =X 2 ) = β 0 + β 1 (X 1 )+ β 2 X 2 n log-odds = β 1 β 1 s the change n log-odds for a 1 unt change n X 1 provded X 2 s held constant. 15
16 Interpretaton n General Also: log = β odds(y = 1 X odds(y = 1 X + 1,X,X 1 And: OR = exp(β 1 )!! exp(β 1 ) s the multplcatve change n odds for a 1 unt ncrease n X 1 provded X 2 s held constant. ) 2 The result s smlar for X 2 ) What f the effects of each of X 1 and X 2 depend on the presence of the other? Effect modfcaton! 16
17 Data: Coronary Heart Dsease (CHD), Smokng and Coffee n =
18 Study Informaton Study Facts: Case-Control study (dsease = CHD) year-old males prevously n good health Study questons: Is smokng and/or coffee related to an ncreased odds of CHD? Is the assocaton of coffee wth CHD hgher among smokers? That s, s smokng an effect modfer of the coffee-chd assocatons? 18
19 Fracton wth CHD by smokng and coffee Number n each cell s the proporton of the total number of ndvduals wth that smokng/coffee combnaton that have CHD 19
20 Pooled data (gnorng smokng) Odds rato of CHD comparng coffee to noncoffee drnkers.53/(1.34 /(1.53).34) = % CI = (1.14, 4.24) 20
21 Among Non-Smokers P(CHD Coffee drnker) = 15/(15+21) = 0.42 P(CHD Not Coffee drnker) = 15/(15+42) = 0.26 Odds rato of CHD comparng coffee to noncoffee drnkers.42 /(1.26 /(1.42).26) = % CI = (0.82, 4.9) 21
22 Among Smokers P(CHD Coffee drnker) = 25/(25+14) = 0.64 P(CHD Not Coffee drnker) = 11/(11+8) = 0.58 Odds rato of CHD comparng coffee to noncoffee drnkers.64 /(1.58/(1.64).58) = % CI = (0.42, 4.0) 22
23 Plot Odds Ratos and 95% CIs 23
24 Defne Varables Y = 1 f CHD case, 0 f control coffee = 1 f Coffee Drnker, 0 f not smoke = 1 f Smoker, 0 f not p = Pr (Y = 1) n = Number observed at pattern of Xs 24
25 Logstc Regresson Model Y are ndependent Random part Y are from a Bnomal (n, p ) dstrbuton Systematc part log odds (Y =1) (or logt( Y =1) ) s a functon of Coffee Smokng and coffee-smokng nteracton p log = + coffee + smoke p β0 β1 β2 1 + β coffee 3 smoke 25
26 Interpretatons stratfy by smokng status p log 1 p If smoke = 0 If smoke = 1 p = β0 + β1coffee p log 1 p + β smoke exp(β 1 ): odds rato of beng a CHD case for coffee drnkers -vs- non-drnkers among non-smokers exp(β 1 +β 3 ): odds rato of beng a CHD case for coffee drnkers -vs- non-drnkers among smokers 2 + β coffee = β 0 + β1coffee 3 smoke log = β 0 + β1coffee + β2 1+ β3coffee 1 = ( β0 + β2) + ( β1 + β3 1 p ) coffee 26
27 Interpretatons stratfy by coffee drnkng p log 1 p If coffee = 0 If coffee = 1 p = β0 + β1coffee + β2smoke + β3coffee p log = β 0 + β2smoke 1 p smoke log = β 0 + β1 1+ β2smoke + β31 smoke = ( β0 + β1) + ( β2 + β3 1 p exp(β 2 ): odds rato of beng a CHD case for smokers -vs- non-smokers among noncoffee drnkers exp(β 2 +β 3 ): odds rato of beng a CHD case for smokers -vs- non-smokers among coffee drnkers ) smoke 27
28 Interpretatons p log 1 p = β + 0 β coffee 1 + β smoke 2 + β coffee 3 smoke e β 0 β Probablty of CHD f all X s are zero e.e., fracton of cases among non- smokng noncoffee drnkng ndvduals n the sample (determned by samplng plan) exp(β 3 ): rato of odds ratos What do we mean by ths? 28
29 exp(β 3 ) Interpretatons p log 1 p = β + β coffee β smoke 2 + β coffee 3 smoke exp(β 3 ): factor by whch odds rato of beng a CHD case for coffee drnkers -vs- nondrnkers s multpled for smokers as compared to non-smokers or exp(β 3 ): factor by whch odds rato of beng a CHD case for smokers -vs- non-smokers s multpled for coffee drnkers as compared to non-coffee drnkers COMMON IDEA: Addtonal multplcatve change n the odds rato beyond the smokng or coffee drnkng effect alone when you have both of these rsk factors present 29
30 Some Specal Cases: No smokng or coffee drnkng effects Gven p log coffee p = β0 + β1 1 If β 1 = β 2 = β 3 = 0 + β smoke 2 + β coffee 3 smoke Nether smokng nor coffee drnkng s assocated wth ncreased rsk of CHD 30
31 Some Specal Cases: Only one effect Gven p log 1 p = β0 + β1coffee + β smoke If β 2 = β 3 = 0 Coffee drnkng, but not smokng, s assocated wth ncreased rsk of CHD If β 1 = β 3 = 0 Smokng, but not coffee drnkng, s assocated wth ncreased rsk of CHD 2 + β coffee 3 smoke 31
32 Some Specal Cases p log 1 p = β0 + β1coffee + β smoke If β 3 = 0 Smokng and coffee drnkng are both assocated wth rsk of CHD but the odds rato of CHD-smokng s the same at both levels of coffee Smokng and coffee drnkng are both assocated wth rsk of CHD but the odds rato of CHD-coffee s the same at both levels of smokng Common dea: the effects of each of these rsk factors s purely addtve (on the log-odds scale), there s no nteracton 2 + β coffee 3 smoke 32
33 Model 1: man effect of coffee p log 1 p = β + 0 β coffee 1 Logt estmates Number of obs = 151 LR ch2(1) = 5.65 Prob > ch2 = Log lkelhood = Pseudo R2 = chd Coef. Std. Err. z P> z [95% Conf. Interval] coffee (Intercept)
34 Model 2: man effects of coffee and smoke p log 1 p = β + β coffee + β smoke Logt estmates Number of obs = 151 LR ch2(2) = Prob > ch2 = Log lkelhood = Pseudo R2 = chd Coef. Std. Err. z P> z [95% Conf. Interval] coffee smoke (Intercept)
35 Model 3: man effects of coffee and smoke AND ther nteracton p log 1 p = β + 0 β coffee 1 + β smoke 2 + β coffee 3 smoke Logt estmates Number of obs = 151 LR ch2(3) = Prob > ch2 = Log lkelhood = Pseudo R2 = chd Coef. Std. Err. z P> z [95% Conf. Interval] coffee smoke coffee_smoke (Intercept)
36 Comparng Models 1 & 2 Queston: Is smokng a confounder? Varable Intercept Coffee Est se Model z Intercept Coffee Smokng Model
37 Look at Confdence Intervals Wthout Smokng OR = e 0.79 = % CI for log(or): 0.79 ± 1.96(0.33) = (0.13, 1.44) 95% CI for OR: (e 0.13, e 1.44 ) = (1.14, 4.24) Wth Smokng (adjustng for smokng) OR = e 0.53 = 1.7 Smokng does not confound the relatonshp between coffee drnkng and CHD snce 1.7 s n the 95% CI from the model wthout smokng 37
38 Concluson regardng confoundng So, gnorng smokng, the CHD and coffee OR s 2.2 (95% CI: ) Adjustng for smokng, gves more modest evdence for a coffee effect However, smokng does not appear to be an mportant confounder 38
39 Interacton Model Queston: Is smokng an effect modfer of CHDcoffee assocaton? Varable Est se z Model 3 Intercept Coffee Smokng Coffee*Smokng
40 Testng Interacton Term Z= -0.59, p-value = We fal to reject H 0 : nteracton slope= 0 And we conclude there s lttle evdence that smokng s an effect modfer! 40
41 Queston: Model selecton What model should we choose to descrbe the relatonshp of coffee and smokng wth CHD? 41
42 Ftted Values We can use transform to get ftted probabltes and compare wth observed proportons usng each of the three models Model 1: Model 2: Model 3: pˆ pˆ e = 1+ = pˆ = e 1+ e Coffee Coffee e Coffee+ 1.1Smokng Coffee+ 1.1Smokng e Coffee+ 1.3Smokng-.43(Coffee*Smokng) 1+ e Coffee+ 1.3Smokng-.43(Coffee*Smokng) 42
43 Observed vs Ftted Values 43
44 Saturated Model Note that ftted values from Model 3 exactly match the observed values ndcatng a saturated model that gves perfect predctons Although the saturated model wll always result n a perfect ft, t s usually not the best model (e.g., when there are contnuous covarates or many covarates) 44
45 Lkelhood Rato Test The Lkelhood Rato Test wll help decde whether or not addtonal term(s) sgnfcantly mprove the model ft Lkelhood Rato Test (LRT) statstc for comparng nested models s -2 tmes the dfference between the log lkelhoods (LLs) for the Null -vs- Extended models We ve already done ths earler n today s lecture!! Ch-square (X 2 ) Test of Devance s the same thng as the Lkelhood Rato Test Used to compare any par of nested logstc regresson models and get a p-value assocated wth the H 0 : the new β s all=0 45
46 Example summary wrte-up A case-control study was conducted wth 151 subjects, 66 (44%) of whom had CHD, to assess the relatve mportance of smokng and coffee drnkng as rsk factors. The observed fractons of CHD cases by smokng, coffee strata are 46
47 Example Summary: Unadjusted ORs The odds of CHD was estmated to be 3.4 tmes hgher among smokers compared to non-smokers 95% CI: (1.7, 7.9) The odds of CHD was estmated to be 2.2 tmes hgher among coffee drnkers compared to non-coffee drnkers 95% CI: (1.1, 4.3) 47
48 Example Summary: Adjusted ORs Controllng for the potental confoundng of smokng, the coffee odds rato was estmated to be 1.7 wth 95% CI: (.85, 3.4). Hence, the evdence n these data are nsuffcent to conclude coffee has an ndependent effect on CHD beyond that of smokng. 48
49 Example Summary: effect modfcaton Fnally, we estmated the coffee odds rato separately for smokers and non-smokers to assess whether smokng s an effect modfer of the coffee-chd relatonshp. For the smokers and non-smokers, the coffee odds rato was estmated to be 1.3 (95% CI:.42, 4.0) and 2.0 (95% CI:.82, 4.9) respectvely. There s lttle evdence of effect modfcaton n these data. 49
50 Summary of Lecture 15 Includng categorcal predctors n logstc regresson create dummy/ndcator varables just lke for lnear regresson Comparng nested models that dffer by two or more varables for logstc regresson Ch-square (X 2 ) Test of Devance.e., lkelhood rato test analogous to the F-test for nested models n lnear regresson Effect Modfcaton and Confoundng n logstc regresson 50
Spatiotemporal Analysis of Marriage and Marital Fertility in Japan: Using Geographically Weighted Regression
Spatotemporal Analyss of Marrage and Martal ertlty n Japan: Usng Geographcally Weghted Regresson 1980-2010 Kenj Kamata (Natonal Insttute of Populaton and Socal Securty Research) Abstract (125) Ths study
More informationCan Survey Bootstrap Replicates Be Used for Cross-Validation?
Secton on Survey Researc Metods JSM 2008 Can Survey Bootstrap Replcates Be Used for Cross-Valdaton? Geoff Rowe 1 and Davd Bnder 2 1 Geoff Rowe, Statstcs Canada, Tunney's Pasture, Ottawa, ON, K1A 0T6, Canada;
More informationThe Policy Performance of NFSF and Slippage in Futures Markets
Po-Ka Huang The Polcy Performance of NFSF and Slppage n Futures Markets (Receved Apr 28, 2011; Frst Revson Jun 8, 2012; Second Revson Dec 12, 2013; Accepted Jan 16, 2014) Introducton * Government nterventons
More informationWeight Gain During the Transition to Adulthood among Children of Immigrants: Is Parental Co-residence Important? Elizabeth Baker
Weght Gan Durng the Transton to Adulthood among Chldren of Immgrants: Is Parental Co-resdence Important? Elzabeth Baker Abstract Immgrants tend to be healther than ther natve born peers, despte ther low
More informationFaculty Research Working Papers Series
Faculty Research Workng Papers Seres Socal Interactons and Smokng Davd Cutler Department of Economcs Harvard Unversty Edward L. Glaeser Department of Economcs & John F. Kennedy School of Government Harvard
More informationThe labour market impacts of adult education and training in Canada
Catalogue no. 81-595-MIE No. 008 ISSN: 1704-8885 ISBN: 0-662-34802-8 Research Paper Educaton, sklls and learnng Research papers The labour market mpacts of adult educaton and tranng n Canada by Shek-wa
More informationThe Rise of Obesity in Transition Economies: Theory and Evidence from the Russian Longitudinal Monitoring Survey
Economcs Presentatons, Posters and Proceedngs Economcs 2008 The Rse of Obesty n Transton Economes: Theory and Evdence from the Russan Longtudnal Montorng Survey Sonya K. Huffman Iowa State Unversty, skostova@astate.edu
More informationExperimental and Numerical Studies on Flocculation of Sand-Mud Suspensions
MASTS Numercal & Expermental Hydrodynamc Modellng Forum Workshop Grassmarket Centre Ednburgh 9th Aprl 208 Expermental and Numercal Studes on Flocculaton of Sand-Mud Suspensons Dr Alan Cuthbertson Senor
More informationResource Allocation for Cocoyam and Coffee Production in Momo, North West Region of Cameroon
Kamla-Raj 2013 J Hum Ecol, 41(2): 175-11 (2013) Resource Allocaton for Cocoyam and Coffee Producton n Momo, North West Regon of Cameroon Dorothy E. Fon Department of Agrcultural Economcs, Unversty of Dschang,
More informationCoffee Differentiation: Demand Analysis at Retail Level in the US Market
Coffee Dfferentaton: Demand Analyss at Retal Level n the US Market Carmen Alamo and Jame Malaga Texas Tech Unversty Department of Agrculture and Appled Economcs Lubbock, Texas Phone: 806-742-1921 E-mals:
More informationTrade liberalization and labour markets:
EMPLOYMENT PAPER 2002/41 Trade lberalzaton and labour markets: Perspectve from OECD economes Mchael Landesmann Robert Stehrer Sandra Letner Employment Sector INTERNATIONAL LABOUR OFFICE GENEVA EMPLOYMENT
More informationDemand Analysis of Non-Alcoholic Beverages in Japan
Journal of Agrcultural Scence; Vol. 7, No. 5; 2015 ISSN 1916-9752 E-ISSN 1916-9760 Publshed by Canadan Center of Scence and Educaton Demand Analyss of Non-Alcoholc Beverages n Japan Mchael Fesseha Yohannes
More informationWilliam C. Hunter. Julapa Jagtiani
MERGER ADVISORY FEES AND ADVISORS EFFORT Wllam C. Hunter Julapa Jagtan Emergng Issues Seres Supervson and Regulaton Department Federal Reserve Bank of Chcago December 2000 (S&R-2000-11R) Merger Advsory
More informationEthnic Sorting in the Netherlands
DISCUSSION PAPER SERIES IZA DP No 3155 Ethnc Sortng n the Netherlands Aslan Zorlu Jan Latten November 2007 Forschungsnsttut zur Zukunft der Arbet Insttute for the Study of Labor Ethnc Sortng n the Netherlands
More informationModelling Beta Risk for New Zealand Industry Portfolios
Modellng Beta Rsk for New Zealand Industry Portfolos Xao-Mng L Department of Commerce, Massey Unversty (Albany), New Zealand Abstract In modellng the beta rsk of the New Zealand ndustry portfolos, we extend
More informationThe Flower of Paradise: Substitution or Income Effect? Sara Borelli University of Illinois at Chicago
The Flower of Paradse: Substtuton or Income Effect? Sara Borell Unversty of Illnos at Chcago Abstract The am of ths paper s to evaluate the mpact of a wage ncrease on Qat consumpton for the Djboutan mal
More informationMigration and Fertility: Competing Hypotheses Re-examined
Max-Planck-Insttut für demografsche Forschung Max Planck Insttute for Demographc Research Konrad-Zuse-Strasse 1 D-18057 Rostock GERMANY Tel +49 (0) 3 81 20 81-0; Fax +49 (0) 3 81 20 81-202; http://www.demogr.mpg.de
More informationInvestigation of factors affecting consumers bread wastage
Journal of Agrcultural Economcs and Development Vol. 2(6), pp. 246-254, June 2013 Avalable onlne at http://academeresearchjournals.org/journal/jaed ISSN 2327-3151 2013 Academe Research Journals Full Length
More informationYIELD AND COMPOSITIONAL DIFFERENCES BETWEEN SELECTIONS OF GRAPEVINE CV. CABERNET SAUVIGNON
YELD AND COMPOSTONAL DFFERENCES BETWEEN S OF GRAPEVNE CV. CABERNET SAUVGNON J. R. Whtng and W. J. Harde Sunraysa Hortcultural Research nsttute, Mldura, 35. R. M. Cram, formerly of the Department, nstgated
More informationFactors Affecting Frequency of Fast Food Consumption
Volume 49, Issue 1 Factors Affectng Frequency of Fast Food Consumpton Sayed Saghaan a! and Hosen Mohammad b a Professor, Department of Agrcultural Economcs, Unversty of Kentucky, 314 Barnhart Buldng, Lexngton,
More information'""' USAFA/ Coord.{!tr lv~ ""' DFCE... ~A.., USAFA/ DFER. Sign C:.dl A:>.-').l'. 23 \,;'~ rs- 7 USAFA-DF-PA- CJ
STAFF SUMMARY SHEET "" TO ACTON SGNATURE (Surname), GRADE AND DATE :: TO ACTON SGNATURE (Surname), GRADE AND DATE USAFA/ Coord.{tr lv "" 1 6 2 DFCE... A..,. 1111 USAFA/ DFER Sgn C:.dl A:>.-).l. 23 \,;
More informationSchool Breakfast and Lunch Costs: Are There Economies of Scale? Authors. Michael Ollinger, Katherine Ralston, and Joanne Guthrie
School Breakfast and Lunch osts: Are There Economes of Scale? Authors Mchael Ollnger, Katherne Ralston, and Joanne Guthre ontact Informaton Mchael Ollnger, Economc Research Servce, USDA, 1800 M Street
More informationLABOUR UNIONS AND WAGE INEQUALITY AMONG AFRICAN MEN IN SOUTH AFRICA
LABOUR UNIONS AND WAGE INEQUALITY AMONG AFRICAN MEN IN SOUTH AFRICA MIRACLE NTULI PRUDENCE KWENDA DPRU WORKING PAPER 13/159 DECEMBER 2013 LABOUR UNIONS AND WAGE INEQUALITY AMONG AFRICAN MEN IN SOUTH AFRICA
More informationThe Exchange Rate and the Performance of Japanese Firms: A Preliminary Analysis Using Firm-level Panel Data
Prelmnary The Echange Rate and the Performance of Japanese Frms: A Prelmnary Analyss Usng Frm-level Panel Data Takash Hanagak and Masahro Hor (Economc and Socal Research Insttute, Cabnet Offce, JAPAN)
More informationFurther Evidence on Finance-Growth Causality: A Panel Data Analysis
Further Evdence on Fnance-Growth Causaly: A Panel Data Analyss Chrysost BANGAKE Laboratore d Econome d Orléans (LEO), Unversé d Orléans. Faculté de Dro, d Econome et de Geston. Rue de Blos BP : 6739. 45067
More informationepub WU Institutional Repository
epub WU Insttutonal Repostory Harald Badnger and Frtz Breuss Trade and productvty. An ndustry perspectve. Paper Orgnal Ctaton: Badnger, Harald and Breuss, Frtz (2005) Trade and productvty. An ndustry perspectve.
More informationForecasting Harvest Area and Production of Strawberry Using Time Series Analyses
Gazosmanpaşa Ünverstes Zraat Fakültes Dergs Journal of Agrcultural Faculty of Gazosmanpasa Unversty http://zraatderg.gop.edu.tr/ Araştırma Makales/Research Artcle JAFAG ISSN: 1300-2910 E-ISSN: 2147-8848
More informationFood Marketing Policy Center
Food Marketng Polcy Center Market Power and/or Effcency: An Applcaton to U.S. Food Processng by Rgoberto A. Lopez, Azzedne M. Azzam, and Carmen Lrón-España Food Marketng Polcy Center Research Report No.
More informationGail E. Potter, Timo Smieszek, and Kerstin Sailer. April 24, 2015
Supplementary Material to Modelling workplace contact networks: the effects of organizational structure, architecture, and reporting errors on epidemic predictions, published in Network Science Gail E.
More informationDemand for meat quantitu and quality in Malaysia: Implications to Australia
MPRA Munch Personal RePEc Archve Demand for meat quanttu and qualty n Malaysa: Implcatons to Australa (John) Yeong-Sheng Tey and Fatmah Mohamed Arshad and Mad Nasr Shamsudn and Zanalabdn Mohamed and Alas
More informationCatching up or falling behind in Eastern European agriculture the case of milk production
Catchng up or fallng behnd n Eastern European agrculture the case of mlk producton Lukas Cechura, Aaron Grau 2, Henrch Hockmann 2, Inna Levkovych 2, Zdenka Kroupova Czech Unversy of Lfe Scences Prague
More informationThe Pennsylvania State University. The Graduate School. College of Agricultural Sciences ESSAYS ON WELFARE USE, THE WAGE GAP AND UNEMPLOYMENT
The Pennsylvana State Unversty The Graduate School College of Agrcultural Scences ESSAYS ON WELFARE USE, THE WAGE GAP AND UNEMPLOYMENT TRANSITIONS IN THE UNITED STATES A Thess n Agrcultural, Envronmental
More informationTo: Professor Roger Bohn & Hyeonsu Kang Subject: Big Data, Assignment April 13th. From: xxxx (anonymized) Date: 4/11/2016
To: Professor Roger Bohn & Hyeonsu Kang Subject: Big Data, Assignment April 13th. From: xxxx (anonymized) Date: 4/11/2016 Data Preparation: 1. Separate trany variable into Manual which takes value of 1
More informationPSYC 6140 November 16, 2005 ANOVA output in R
PSYC 6140 November 16, 2005 ANOVA output in R Type I, Type II and Type III Sums of Squares are displayed in ANOVA tables in a mumber of packages. The car library in R makes these available in R. This handout
More informationThe Qualities of Albanian Soft Wheat Genotypes the Mathematical Approach
Internatonal Journal of Scence and Qualtatve Analyss 2015; 1(2): 11-17 Publshed onlne June 10, 2015 (http://www.scencepublshnggroup.com/j/jsqa) do: 10.11648/j.jsqa.20150102.11 The Qualtes of Albanan Soft
More informationEstimation of State-by-State Trade Flows for Service Industries *
Estmaton of State-by-State Trade Flows for Servce Industres * JYoung Park ** Von Klensmd Center 382 School of Polcy, Plannng, and Development Unversty of Southern Calforna Los Angeles, CA 90089-0001 Emal:
More information2
2 3 4 5 6 7 8 9 10 11 *** *** *** *** *** *** *** *** *** ** * 12 Mixed logit model Number of obs = 7896 LR chi2(9) = 154.97 Log likelihood = -2139.5089 Prob > chi2 = 0.0000 ------ choice Coef. Std. Err.
More informationInventory Decision Model of Single-echelon and Two-indenture Repairable Spares
Te nd nternatonal Conference on Computer Applcaton and System Modelng (0 nventory Decson Model of Sngle-ecelon and Two-ndenture Reparable Spares Lu Cenyu Naval Aeronautcal and Astronautcal Unversty Qngdao
More informationwine 1 wine 2 wine 3 person person person person person
1. A trendy wine bar set up an experiment to evaluate the quality of 3 different wines. Five fine connoisseurs of wine were asked to taste each of the wine and give it a rating between 0 and 10. The order
More informationAN EVALUATION OF TRAINING
Offce of Evaluaton and Oversght AN EVALUATION OF TRAINING FOR THE UNEMPLOYED IN MEXICO Marcelo Delajara, Samuel Freje, Isdro Soloaga * Workng Paper: OVE/WP-09/06 September, 2006 Electronc verson: http://ove/oveintranet/defaultnocache.aspx?acton=wucpublcatons@impactevaluatons
More informationDesigning Ranking Systems for Hotels on Travel Search Engines by Mining User-Generated and Crowdsourced Content
Unversty of Pennsylvana ScholarlyCommons Operatons, Informaton and Decsons Papers Wharton Faculty Research 5-2012 Desgnng Ranng Systems for Hotels on Travel Search Engnes by Mnng User-Generated and Crowdsourced
More informationThe Optimal Wine. A Study in Design Optimization. April 26, Erin MacDonald Alexis Lubensky Bryon Sohns
The Optmal ne A Study n Desgn Optmzaton Aprl 6, 004 Ern MacDonald Alexs Lubensky Bryon Sohns Unversty of Mchgan ME 555 Desgn Optmzaton Professor Panos Y. Papalambros Unversty of Mchgan Table of ontents
More informationDominance Testing for Pro-Poor Growth with an Application to European Growth
Domnance Testng for Pro-Poor Growth wth an Alcaton to Euroean Growth DANIEL SOTELSEK SALEM, ISMAEL AHAMDANECH ZARCO and JOHN. A BISHOP. IELAT (Latn Amercan Studes Insttute). Av/ Juan Carlos I, 7. 8806.
More informationProtein Isolation from Tomato Seed Meal, Extraction Optimization
Proten Isolaton from Tomato Seed Meal, Extracton Optmzaton GEORGE N. LIADAKIS, CONSTANTINA TZIA, VASSILIKI OREOPOULOU, and CHRISTOS D. THOMOPOULOS ABSTRACT Water extracton of tomato seed meal protens was
More informationHW 5 SOLUTIONS Inference for Two Population Means
HW 5 SOLUTIONS Inference for Two Population Means 1. The Type II Error rate, β = P{failing to reject H 0 H 0 is false}, for a hypothesis test was calculated to be β = 0.07. What is the power = P{rejecting
More informationNorthern Region Central Region Southern Region No. % of total No. % of total No. % of total Schools Da bomb
Some Purr Words Laurie and Winifred Bauer A number of questions demanded answers which fell into the general category of purr words: words with favourable senses. Many of the terms supplied were given
More informationDELINEATION OF DISEASED TEA PATCHES USING MXL AND TEXTURE BASED CLASSIFICATION
DELIEATIO OF DISEASED TEA PATCHES USIG MXL AD TEXTURE BASED CLASSIFICATIO Rshra Dutta a, *, Alfred Sten a,.r. Patel b a Department of Earth Observaton Scence, Internatonal Insttute for Geonformaton Scence
More informationTable 1: Number of patients by ICU hospital level and geographical locality.
Web-based supporting materials for Evaluating the performance of Australian and New Zealand intensive care units in 2009 and 2010, by J. Kasza, J. L. Moran and P. J. Solomon Table 1: Number of patients
More informationEstimation of State-by-State Trade Flows for Service Industries *
Estmaton of State-by-State Trade Flows for Servce Industres * JYoung Park ** Von Klensmd Center 382 School of Polcy, Plannng, and Development Unversty of Southern Calforna Los Angeles, CA 90089-0001 Emal:
More informationThe R survey package used in these examples is version 3.22 and was run under R v2.7 on a PC.
CHAPTER 7 ANALYSIS EXAMPLES REPLICATION-R SURVEY PACKAGE 3.22 GENERAL NOTES ABOUT ANALYSIS EXAMPLES REPLICATION These examples are intended to provide guidance on how to use the commands/procedures for
More informationQUICK START GUIDE Armonia
QUICK START GUIDE Armona C O F F E E M A C H I N E S MACHINE DESCRIPTION LEGEND. PRODUCT CANISTER. PRODUCT CANISTER / CEE HOPPER. CEE HOPPER. CARD READER. DECAFFEINATED DOOR. DOSE BUTTON. SERVICE KEYPAD
More informationEvaluation Method of Banking System Stability Based on the Volume of Subsystems
Journal of Fnance and Economcs 204 ol. 2 o. 4 8-24 Avalable onlne at ttp://pubs.scepub.com/jfe/2/4/3 Scence and Educaton Publsng DOI:0.269/jfe-2-4-3 Evaluaton Metod of ankng System Stablty ased on te olume
More informationComparing R print-outs from LM, GLM, LMM and GLMM
3. Inference: interpretation of results, plotting results, confidence intervals, hypothesis tests (Wald,LRT). 4. Asymptotic distribution of maximum likelihood estimators and tests. 5. Checking the adequacy
More informationDevelopment, maturation, and postharvest responses of Actinidia arguta (Sieb. et Zucc.) Planch, ex Miq. fruit
New Zeala Journal of Crop a Hortcultural Scence ISSN: 04-067 (Prnt) 75-8783 (Onlne) Journal homepage: http://www.tafonlne.com/lo/tnzc20 Development, maturaton, a postharvest responses of Actnda arguta
More informationHeat Spreading Revisited Effective Heat Spreading Angle
Heat Spreadng Revsted Effectve Heat Spreadng Angle Drk Schwetzer and Lu Chen Infneon Technologes AG Am Campeon -, 85579 Neubberg, Germany drk.schwetzer@nfneon.com Abstract There s probably no thermal engneer
More informationPreferred citation style
Preferred citation style Axhausen, K.W. (2016) How many cars are too many? A second attempt, distinguished transport lecture at the University of Hong Kong, Hong Kong, October 2016.. How many cars are
More informationThe premium for organic wines
Enometrics XV Collioure May 29-31, 2008 Estimating a hedonic price equation from the producer side Points of interest: - assessing whether there is a premium for organic wines, and which one - estimating
More informationMekelle University College of Business and Economics Department of Economics
Mekelle Unversty College of Busness and Economcs Department of Economcs The Impact of Camel Transportaton on the Lvelhood of Pastoralsts: In Berahle Woreda, Afar Regonal State of Ethopa BY: SELAMAWIT TEKLU
More informationOPERATING INSTRUCTIONS
venna dgtal OPERATING INSTRUCTIONS READ THESE OPERATING INSTRUCTIONS CAREFULLY BEFORE USING THE MACHINE FOR HOUSEHOLD USE ONLY Congratulatons! Congratulatons on choosng ths top-qualty espresso machne and
More informationRelationships Among Wine Prices, Ratings, Advertising, and Production: Examining a Giffen Good
Relationships Among Wine Prices, Ratings, Advertising, and Production: Examining a Giffen Good Carol Miu Massachusetts Institute of Technology Abstract It has become increasingly popular for statistics
More informationDevelopment and application of a rural water supply assessment tool in Brazil
Development and applcaton of a rural water supply assessment tool n Brazl W. T. P. Slva 1,2, A. A. Santos 3 and M. A. A. Souza 1 1 Post-graduate Program on Envronmental Tecnology and Water Resources, Department
More informationImpacts of U.S. Sugar Policy and the North American Free Trade Agreement on Trade in North American Sugar Containing Products
Impacts of U.S. Sugar Polcy and the North Amercan Free Trade Agreement on Trade n North Amercan Sugar ontanng Products Ross Prutt Danel S. Tlley* Selected Paper prepared for Presentaton at the Amercan
More informationAJAE Appendix: Testing Household-Specific Explanations for the Inverse Productivity Relationship
AJAE Appendix: Testing Household-Specific Explanations for the Inverse Productivity Relationship Juliano Assunção Department of Economics PUC-Rio Luis H. B. Braido Graduate School of Economics Getulio
More informationGuatemala. 1. Guatemala: Change in food prices
Appendix I: Impact on Household Welfare: Guatemala 1. Guatemala: Change in food prices Group dp1 dp2 1. Rice 12.87% 10.00% 2. Corn 5.95% 10.00% 3. Bread and dried 29.17% 10.00% 4. Beans, roots, vegetables
More informationECOLOGICAL STUDIES OF CTENOSCIARA HAWAIIENSIS (HARDY) (Diptera: Sciaridae) 2
Pacfc Insects 15 (1): 85-94 20 May 1973 ECOLOGICAL STUDIES OF CTENOSCIARA HAWAIIENSIS (HARDY) (Dptera: Scardae) 2 By Wallace A. Steffan 1 Abstract: The seasonal fluctuatons of Ctenoscara hawaenss (Hardy)
More informationMultiple Imputation for Missing Data in KLoSA
Multiple Imputation for Missing Data in KLoSA Juwon Song Korea University and UCLA Contents 1. Missing Data and Missing Data Mechanisms 2. Imputation 3. Missing Data and Multiple Imputation in Baseline
More informationStatistics: Final Project Report Chipotle Water Cup: Water or Soda?
Statistics: Final Project Report Chipotle Water Cup: Water or Soda? Introduction: For our experiment, we wanted to find out how many customers at Chipotle actually get water when they order a water cup.
More informationSponsored by: Center For Clinical Investigation and Cleveland CTSC
Selected Topics in Biostatistics Seminar Series Association and Causation Sponsored by: Center For Clinical Investigation and Cleveland CTSC Vinay K. Cheruvu, MSc., MS Biostatistician, CTSC BERD cheruvu@case.edu
More informationBORDEAUX WINE VINTAGE QUALITY AND THE WEATHER ECONOMETRIC ANALYSIS
BORDEAUX WINE VINTAGE QUALITY AND THE WEATHER ECONOMETRIC ANALYSIS WINE PRICES OVER VINTAGES DATA The data sheet contains market prices for a collection of 13 high quality Bordeaux wines (not including
More informationDetection of Yeast Septicemia by Biphasic and Radiometric
JOURNAL OF CLINICAL MICROBIOLOGY, Apr. 1981, p. 655-660 0095-113/81/040655-06$0.00/0 Vol. 13, No. 4 Detecton Yeast Septcema by Bphasc and Radometrc Methods ELENA PREVOST* AND EDWARD BANNISTER Dvson Clncal
More informationRituals on the first of the month Laurie and Winifred Bauer
Rituals on the first of the month Laurie and Winifred Bauer Question 5 asked about practices on the first of the month: 5 At your school, do you say or do something special on the first day of a month?
More informationAN ATTRACTIVENESS-BASED MODEL FOR SHOPPING TRIPS IN URBAN AREAS
Autor manuscrpt, publsed n "12t World Conference on Transport Researc, Lsbonne : Portugal (2010)" An attractveness-based model for soppng trps n urban areas GONZALZ-FLIU, Jesus; ROUTHIR, Jean-Lous; RAUX,
More informationIII. EVALUATION OF COLDPRESSED FLORIDA LEMON OIL AND LEMON
32 FLORIDA STATE HORTICULTURAL SOCIETY, 958 of the three packs contanng juce from each of the 42 lemon selectons. The effect of stor age for one year at -8 F. on the flavor of these concentrates has not
More informationCardiff Economics Working Papers
Cardff Economcs Workng Papers Workng Paper No. E2007/5 Ratonal Ineffcency and non-performng loans n Chnese Bankng: A non-parametrc Bootstrappng Approach. Kent Matthews, Janguang Guo and Nna Zhang February
More informationI - 1 The IBPGR was requested to: 1. recognize the two designated ISSCT world collections; 2. establish seed repositories; and
REPORT OF THE STANDNG COMMTTEE ON GERMPLASM AND BREEDNG The actvtes of the Commttee have been lmted durng the past three years. collected durng the 1976 and 1977 cane collecton expedtons n ndonesa and
More informationMissing Data Methods (Part I): Multiple Imputation. Advanced Multivariate Statistical Methods Workshop
Missing Data Methods (Part I): Multiple Imputation Advanced Multivariate Statistical Methods Workshop University of Georgia: Institute for Interdisciplinary Research in Education and Human Development
More informationConsumer Price Indices
Consumer Prce ndces Metodologcal note Te Consumer Prce ndex for te wole naton (NC) s based on te consumpton of te entre present populaton. Te Harmonsed ndex of Consumer Prces (HCP), calculated accordng
More informationInterannual Herbaceous Biomass Response to Increasing Honey Mesquite Cover on Two Soils
Rangeland Ecol Manage 61:496 508 September 2008 Interannual Herbaceous Bomass Response to Increasng Honey Mesqute Cover on Two Sols W. Rcard Teague, 1 R. Jm Ansley, 1 Wllam E. Pncak, 1 Steven L. Dowower,
More informationPepero Day: Creation and Evolution of a Holiday
MPRA Munch Personal RePEc Archve Pepero Day: Creaton and Evoluton of a Holday Brandon Walcutt Hankuk Unversty of Foregn Studes 1. December 2014 Onlne at http://mpra.ub.un-muenchen.de/63774/ MPRA Paper
More informationTechnical Memorandum: Economic Impact of the Tutankhamun and the Golden Age of the Pharoahs Exhibition
Technical Memorandum: Economic Impact of the Tutankhamun and the Golden Age of the Pharoahs Exhibition Prepared for: The Franklin Institute Science Museum Prepared by: Urban Partners November 2007 Economic
More information(12) United States Patent Jaswal et a].
US008568817B2 (12) Unted States Patent Jaswal et a]. (10) Patent N0.: () Date of Patent: Oct. 29, 13 (54) CREAM SUBSTITUTE (75) Inventors: Varnder Sngh JasWal, Rchmond Vctora (AU); Joanne Dxon, Cheltenham
More informationYou know what you like, but what about everyone else? A Case study on Incomplete Block Segmentation of white-bread consumers.
You know what you like, but what about everyone else? A Case study on Incomplete Block Segmentation of white-bread consumers. Abstract One man s meat is another man s poison. There will always be a wide
More informationSummary of Main Points
1 Model Selection in Logistic Regression Summary of Main Points Recall that the two main objectives of regression modeling are: Estimate the effect of one or more covariates while adjusting for the possible
More informationPro Innova. Quality Like Fresh
Pro Innova Qualty Lke Fresh Pro Innova Qualty Lke Fresh New Products 12.10.2015 Pro Innova have been developng ready-made dshes from Thaland n addton to the Gourmet Cod Lons and Tempura Battered Seafood
More informationEestimated coefficient. t-value
Table 1: Estimated wage curves for men, 1983 2009 Dependent variable: log (real wage rate) Dependent variable: log real wage rate Men 1983-2009 Men, 1983-2009 Rendom-effect Fixed-effect z-vae t-vae Men
More informationMeasuring the impacts of conservation tillage on household income and consumption: A Syrian case
Measuring the impacts of conservation tillage on household income and consumption: A Syrian case Tamer El-Shater 1, Yigezu A. Yigezu 1*, Amin Mugera 2, Colin Piggin 1, Atef Haddad 1, Yaseen Khalil 1, Stephen
More informationWhich of your fingernails comes closest to 1 cm in width? What is the length between your thumb tip and extended index finger tip? If no, why not?
wrong 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 right 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 score 100 98.5 97.0 95.5 93.9 92.4 90.9 89.4 87.9 86.4 84.8 83.3 81.8 80.3 78.8 77.3 75.8 74.2
More informationCALIBRATION ALGORITHM FOR CURRENT-OUTPUT R-2R LADDERS
X MEKO World Congress Measurement - upports cence - mproves Tecnology - Protects Envronment... and Provdes Employment - ow and n te Future enna, AUTA, 000, eptember 5-8 CALBATO ALGOTHM FO CUET-PUT - LADDE
More informationMissing Data Treatments
Missing Data Treatments Lindsey Perry EDU7312: Spring 2012 Presentation Outline Types of Missing Data Listwise Deletion Pairwise Deletion Single Imputation Methods Mean Imputation Hot Deck Imputation Multiple
More informationBiologist at Work! Experiment: Width across knuckles of: left hand. cm... right hand. cm. Analysis: Decision: /13 cm. Name
wrong 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 right 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 score 100 98.6 97.2 95.8 94.4 93.1 91.7 90.3 88.9 87.5 86.1 84.7 83.3 81.9
More informationWEST VOLUNTEER FI RE DEPARTMENT COOK-OFF
WEST VOLUNTEER F RE DEPARTMENT COOKOFF Dear BBQ Cookers, The WVFD cookoff wll only reserve YOUR 2014 STE FOR 2015, f a completed entry form wth that ste number & fully entry fee of $150.00 s receved by
More informationBags not: avoiding the undesirable Laurie and Winifred Bauer
Bags not: avoiding the undesirable Laurie and Winifred Bauer Question 10 asked how children claim the right not to do something: 10 Your class is waiting for the bus to arrive to take you on a trip. You
More informationRaw coffee processing yield affected more by cultivar than by harvest date 12
Raw coffee processng yeld affected more by cultvar than by harvest date 12 Teodoro Espnosa-Solares, 3 Juan Gullermo Cruz-Castllo, 4 sval Antono Montesnos-López 3 and Arturo Hernández-Montes 3 J. Agre.
More informationInfluence of the soil on the transport of the spores of Pastaria penetram, parasite of nematodes of the genus Meloidogyne
..... :., ".'_,., XI I. L EIIC J. Sool Bol., 1996, 32 (2), 8188 Influence of the sol on the transport of the spores of Pastara penetram, paraste of nematodes of the genus Melodogyne Matelle T. ('1, Duponnos
More informationOnline Appendix to The Effect of Liquidity on Governance
Online Appendix to The Effect of Liquidity on Governance Table OA1: Conditional correlations of liquidity for the subsample of firms targeted by hedge funds This table reports Pearson and Spearman correlations
More informationPoisson GLM, Cox PH, & degrees of freedom
Poisson GLM, Cox PH, & degrees of freedom Michael C. Donohue Alzheimer s Therapeutic Research Institute Keck School of Medicine University of Southern California December 13, 2017 1 Introduction We discuss
More informationPractical design approach for trapezoidal modulation of a radio-frequency quadrupole
PHYSICAL REVIEW ACCELERATORS AND BEAMS 1, 03010 (018) Practcal desgn approac for trapezodal modulaton of a rado-frequency quadrupole A. S. Plastun * and P. N. Ostroumov Faclty for Rare Isotope Beams, Mcgan
More informationCurtis Miller MATH 3080 Final Project pg. 1. The first question asks for an analysis on car data. The data was collected from the Kelly
Curtis Miller MATH 3080 Final Project pg. 1 Curtis Miller 4/10/14 MATH 3080 Final Project Problem 1: Car Data The first question asks for an analysis on car data. The data was collected from the Kelly
More informationThe Role of Calorie Content, Menu Items, and Health Beliefs on the School Lunch Perceived Health Rating
The Role of Calorie Content, Menu Items, and Health Beliefs on the School Lunch Perceived Health Rating Matthew V. Pham Landmark College matthewpham@landmark.edu Brian E. Roe The Ohio State University
More information