DEMONSTRATE THE ADVANTAGES OF USING ORDINAL ALPHA WHEN THE ASSUMPTIONS FOR CRONBACHS ALPHA ARE NOT MET; SHOW THE USEFULNESS OF ORDINAL ALPHA WITH THE CHILEAN VERSION OF THE WHO ALCOHOL USE DISORDERS IDENTIFICATION TEST (AUDIT); AND PROVIDE THE COMMANDS IN R PROGRAMMING LANGUAGE FOR PERFORMING THE RESPECTIVE CALCULATIONS.

THE VERIFICATION THAT IN THE FIRMS, PROPERTY AND DIRECTION, THEY ARE SEPARATED FUNCTIONS JUSTIFIES THE STUDY OF HOW INFLUENCE THE DECISIONS OF THE EXECUTIVES AND OF THE OWNERS ON THE AIMS OF THE FIRM, BEING ONE OF THE PRINCIPAL AIMS THE MANAGERIAL RESULTS THAT THE ORGANIZATIONS REACH. METHODOLOGY: THIS STUDY HAS TWO PURPOSES. FIRST, TO REALIZE BRIEF BIBLIOGRAPHICAL REVIEW OF THE THEORY OF AGENCY, AS OF THE ECONOMIC RESULTS, AND SECONDLY, CONTRAST IF THE PRESENCE OF THE EXECUTIVES OR THE OWNERS INFLUENCE THE RESULTS OBTAINED BY THE FIRMS. THE CONTRAST IS REALIZED ON A COMPLETE PANEL OF CHILEAN MANUFACTURING FIRMS, USING THE NATIONAL INDUSTRIAL ANNUAL SURVEY (ENIA) FOR THE PERIOD 2 001-2 007. FINDINGS: USING DESCRIPTIVE ANALYSES AND PANEL DATA TECHNIQUES THERE IS DISCOVERED THAT IN PRESENCE OF EXECUTIVES THE RESULTS OF THE FIRMS ARE TOP, IN RELATION TO THE OBTAINED RESULTS WHEN THE FIRM IS GUIDED BY HIS OWNERS. ORIGINALITY / VALUE OF PAPER: THIS STUDY CONTRIBUTES APPLYING THE FUNDAMENTAL BEGINNING OF THE THEORY OF AGENCY TO A SAMPLE OF CHILEAN FIRMS, CONSIDERING THAT THE MAJORITY OF THESE STUDIES IS APPLIED USUALLY TO THE DEVELOPED COUNTRIES. IN ADITTION UPDATES THE TRADITIONALLY INVESTIGATED PERIOD AND INTRODUCES A PARAGRAPH IN WHICH THERE TEACHES ITSELF THE FORM IN WHICH THE PROGRAMMING IS REALIZED IN R, THAT ALLOWS TO OBTAIN THE RESULTS OF THE STUDY.

IN THIS PAPER, WE STUDY THE PROBLEM OF COEFFICIENTS IDENTIFICATION IN POPULATION GROWTH MODELS. WE CONSIDER THAT THE DYNAMICS OF THE POPULATION IS DESCRIBED BY A SYSTEM OF ORDINARY DIFFERENTIAL EQUATIONS OF SUSCEPTIBLE-INFECTIVE-RECOVERED (SIR) TYPE, AND WE ASSUME THAT WE HAVE A DISCRETE OBSERVATION OF INFECTIVE POPULATION. WE CONSTRUCT A CONTINUOUS OBSERVATION BY APPLYING TIME SERIES AND AN APPROPRIATE FITTING TO THE DISCRETE OBSERVATION DATA. THE IDENTIFICATION PROBLEM CONSISTS IN THE DETERMINATION OF DIFFERENT PARAMETERS IN THE GOVERNING EQUATIONS SUCH THAT THE INFECTIVE POPULATION OBTAINED AS SOLUTION OF THE SIR SYSTEM IS AS CLOSE AS TO THE OBSERVATION. WE INTRODUCE A REFORMULATION OF THE CALIBRATION PROBLEM AS AN OPTIMIZATION PROBLEM WHERE THE OBJECTIVE FUNCTION AND THE RESTRICTION ARE GIVEN BY THE COMPARISON IN THE L2-NORM OF THEORETICAL SOLUTION OF THE MATHEMATICAL MODEL AND THE OBSERVATION, AND THE SIR SYSTEM GOVERNING THE PHENOMENON, RESPECTIVELY. WE SOLVE NUMERICALLY THE OPTIMIZATION PROBLEM BY APPLYING THE GRADIENT METHOD WHERE THE GRADIENT OF THE COST FUNCTION IS OBTAINED BY INTRODUCING AN ADJOINT STATE. IN ADDITION, WE CONSIDER A NUMERICAL EXAMPLE TO ILLUSTRATE THE APPLICATION OF THE PROPOSED CALIBRATION METHOD.

WITH THE AIM OF MITIGATING THE DAMAGE CAUSED BY THE CORONAVIRUS DISEASE 2019 (COVID-19) PANDEMIC, IT IS IMPORTANT TO USE MODELS THAT ALLOW FORECASTING POSSIBLE NEW INFECTIONS ACCURATELY IN ORDER TO FACE THE PANDEMIC IN SPECIFIC SOCIOCULTURAL CONTEXTS IN THE BEST POSSIBLE WAY. OUR FIRST CONTRIBUTION IS EMPIRICAL. WE USE AN EXTENSIVE COVID-19 DATASET FROM NINE LATIN AMERICAN COUNTRIES FOR THE PERIOD OF 1 APRIL 2020 TO 31 DECEMBER 2021. OUR SECOND AND THIRD CONTRIBUTIONS ARE METHODOLOGICAL. WE EXTEND RELEVANT (I) STATE-SPACE MODELS WITH SCORE-DRIVEN DYNAMICS AND (II) NONLINEAR STATE-SPACE MODELS WITH UNOBSERVED COMPONENTS, RESPECTIVELY. WE USE WEEKLY SEASONAL EFFECTS, IN ADDITION TO THE LOCAL-LEVEL AND TREND FILTERS OF THE LITERATURE, FOR (I) AND (II), AND THE NEGATIVE BINOMIAL DISTRIBUTION FOR (II). WE FIND THAT THE STATISTICAL AND FORECASTING PERFORMANCES OF THE NOVEL SCORE-DRIVEN SPECIFICATIONS ARE SUPERIOR TO THOSE OF THE NONLINEAR STATE-SPACE MODELS WITH UNOBSERVED COMPONENTS MODEL, PROVIDING A POTENTIAL VALID ALTERNATIVE TO FORECASTING THE NUMBER OF POSSIBLE NEW COVID-19 INFECTIONS.

DOMESTIC HOT WATER (DHW) CONSUMPTION IN DWELLINGS CAN PLAY A KEY ROLE IN THE DEVELOPMENT OF POLICIES THAT ARE FOCUSED ON ENERGY POVERTY, AND IN IMPROVING ENERGY EFFICIENCY, AMONG OTHER ASPECTS. THERE IS AN IMPORTANT VARIABILITY OBSERVED WITH DHW AMONG DIFFERENT COUNTRIES DUE TO TECHNICAL, SOCIOLOGICAL, CLIMATIC, AND ECONOMIC FACTORS. MOST STUDIES THAT DEAL WITH DHW PREDICTIONS ARE BASED ON STOCHASTIC MODELS, AND ONLY A FEW APPLY TIME SERIES OR STATISTICAL METHODS. IN THE CASE OF CHILE, THE COUNTRY IS UNDERGOING A POLICY DEVELOPMENT PROCESS, AND THERE IS LITTLE INFORMATION ABOUT DHW CONSUMPTION. AS A RESULT, IT IS FUNDAMENTAL TO HAVE DHW CONSUMPTION PREDICTION MODELS THAT ARE FOCUSED ON DWELLING. FOR THIS REASON, THE STUDY ANALYSED THE POSSIBILITY OF USING TIME SERIES MODELS TO MAKE FUTURE ESTIMATIONS ABOUT MONTHLY DOMESTIC HOT WATER (DHW) CONSUMPTION. TO THIS END, CONSUMPTION DATA OBTAINED FROM 98 APARTMENTS BETWEEN 2015 AND 2021 WERE USED, AND 3 APPROACHES WERE APPLIED NAMELY, EXPONENTIAL SMOOTHING, BASIC STRUCTURAL MODEL (BSM), AND STATE-SPACE MODEL (SSM). THE RESULTS SHOWED THAT EXPONENTIAL SMOOTHING AND STATE-SPACE METHODS ALLOWED TO OBTAIN SATISFACTORY RESULTS WITH REGARD TO PERCENTAGE ERROR AND CONFIDENCE LEVELS. THEREFORE, THESE MODELS COULD BE USED TO MAKE FUTURE ESTIMATIONS OF DOMESTIC HOT WATER (DHW) CONSUMPTION.

LOS ESTUDIOS REALIZADOS EN CAMPO Y LABORATORIO MUESTRAN QUE LOS REVESTIMIENTOS FRÍOS (COOL ROOF COATINGS) CONTRIBUYEN A DISMINUIR LAS TRANSFERENCIAS DE CALOR QUE SE DAN A TRAVÉS DE LAS CUBIERTAS, LAS CUALES SON UNA DE LAS PRINCIPALES CAUSAS DE MALESTAR TÉRMICO EN LOS CLIMAS CÁLIDOS Y HÚMEDOS. NO OBSTANTE, NO HAY SUFICIENTES INVESTIGACIONES QUE CUANTIFIQUEN SUS BENEFICIOS EN EL CLIMA TROPICAL Y EXISTE UNA FALTA DE PRECISIÓN TÉCNICA EN GRAN PARTE DEL MATERIAL PUBLICITARIO DE LOS PRODUCTOS DISPONIBLES EN EL MERCADO. POR LO TANTO, CON EL FIN DE REDUCIR ESTA BRECHA EN EL CONOCIMIENTO, EN ESTE ESTUDIO SE ANALIZÓ EL COMPORTAMIENTO TÉRMICO EN CAMPO DE LAS LÁMINAS DE HIERRO GALVANIZADO CON ZINC ANTES Y DESPUÉS DE APLICARLES UN REVESTIMIENTO FRÍO. COMO INDICADOR SE UTILIZÓ LA TEMPERATURA SUPERFICIAL DEL MATERIAL. DURANTE LOS DOS MESES QUE DURÓ EL EXPERIMENTO, SE REALIZARON 95 OBSERVACIONES A DIFERENTES HORAS DEL DÍA, DONDE SE MIDIÓ LA TEMPERATURA SUPERFICIAL DE LA LÁMINA CON Y SIN REVESTIMIENTO Y SE ANOTÓ LA HORA Y EL ESTADO DE NUBOSIDAD DEL CIELO. LOS RESULTANDOS MUESTRAN QUE LA LÁMINA A LA QUE SE LE APLICÓ EL REVESTIMIENTO TIENE UNA TEMPERATURA PROMEDIO 0.85 °C MÁS BAJA. ESTA DIFERENCIA ES ESTADÍSTICAMENTE SIGNIFICATIVA (P = 0.037) Y ES INDEPENDIENTE DE LA HORA DEL DÍA Y DEL ESTADO DE NUBOSIDAD DEL CIELO. NO OBSTANTE ES UN DIFERENCIAL DE TEMPERATURA MENOR AL QUE ENCONTRARON LOS ESTUDIOS PREVIOS.

ENERGY POVERTY (EP) OCCURS WHEN THERE ARE NO ENERGY SERVICES AVAILABLE OR NOT AT AN AFFORDABLE PRICE, OR WHEN HOMES ARE NOT CAPABLE OF MAINTAINING MINIMUM THERMAL COMFORT CONDITIONS. IT IS ASSOCIATED WITH A SERIES OF ADVERSE CONSEQUENCES FOR THE PEOPLES HEALTH AND WITH A HIGHER NUMBER OF DEATHS IN WINTER IN MOST EUROPEAN COUNTRIES. THE OBJECTIVE OF THIS RESEARCH WAS TO STUDY WHETHER THE THERMAL COMFORT LEVELS, THE STATE OF THE DWELLINGS, THE HEATING SYSTEMS, THE ENERGY EXPENSES, THE RESPIRATORY ILLNESSES AND THE MEDICAL EXPENSES REPORTED BY SOCIAL HOUSING INHABITANTS IN CENTRAL-SOUTH CHILE, WERE CORRELATED, TO DETERMINE WHICH VARIABLES OR COMBINATION OF VARIABLES ARE MORE RELATED WITH EP SITUATIONS. TO DEFINE THE THERMAL COMFORT LIMITS, A RECENTLY PUBLISHED ADAPTIVE THERMAL COMFORT MODEL FOR LOW INCOME HOUSING IN CHILE WAS USED. THE RESULTS SHOW THAT A THIRD OF THOSE SURVEYED WERE NOT CAPABLE OF KEEPING THEIR HOME COMFORTABLE FOR AT LEAST 80% OF THE TIME AND MORE THAN A FIFTH WERE INCAPABLE OF DOING SO 65% OF THE TIME. ONLY 10% OF THOSE WHO WERE CAPABLE OF KEEPING COMFORT LEVELS MORE THAN 90% OF THE TIME, SPEND LESS THAN US$ 40 A MONTH, WHICH REPRESENTS 10% OF THE MINIMUM CHILEAN WAGE. REDUCING THE TIME THAT TEMPERATURES ARE BELOW THE LOWER COMFORT LIMIT TO 10% CAN MEAN A REDUCTION IN THE NUMBER OF RESPIRATORY ILLNESSES AND MEDICAL EXPENSES.

BUSINESS PERFORMANCE IS AN ISSUE THAT CONTINUES TO FOCUS THE INTEREST OF RESEARCHERS AND THAT HAS NOT BEEN RESOLVED YET. BASED ON THIS, THE FOLLOWING STUDY HAS TWO MAIN OBJECTIVES: FIRST, TO CONDUCT A LITERATURE REVIEW OF THE FACTORS THAT IMPACT ON FIRM PERFORMANCE; AND SECOND, TO CONTRAST PREVIOUS APPROACHES IN ORDER TO PROVIDE EMPIRICAL EVIDENCE ABOUT THIS ISSUE BY MEANS OF A COMPARATIVE ANALYSIS OF FIRMS IN CHILE AND SPAIN. A CONTRAST OVER A COMPLETE PANEL OF CHILEAN AND SPANISH INDUSTRIAL FIRMS IS PERFORMED BY USING TWO DATABASES FOR EACH COUNTRY, RESPECTIVELY: (I) THE ANNUAL NATIONAL INDUSTRIAL SURVEY (ENIA), AND (II) THE SURVEY OF BUSINESS STRATEGIES (ESEE), BOTH FOR THE PERIOD 2000-2007. USING COMPONENTS FOR THE ANALYSIS OF VARIANCE WE IDENTIFIED THE FACTORS THAT EXPLAIN MORE THAN 90% OF BUSINESS RESULTS, ADDITIONALLY, VIA TECHNIQUES FOR PANEL DATA, WE FOUND THESE FACTORS ALSO INFLUENCE THE RESULTS OBTAINED. THUS, THIS PAPER ADVANCES IN THE DISCUSSION OF THE SUBJECT THROUGH ITS APPLICATION ON FIRMS IN A DEVELOPING COUNTRY SUCH AS CHILE. FURTHERMORE, THIS STUDY ANALYZES A NEGLECTED MATTER IN LITERATURE: THE STUDY OF THE INFLUENCE OF THE FACTORS, WITHOUT FOCUSING ONLY IN THE ANALYSIS OF THE PERCENTAGE OF EXPLANATION OF THE FACTORS BASED ON FIRM PERFORMANCE. AT THE SAME TIME, THIS STUDY SERVES AS AN UPDATE TO THE TRADITIONALLY RESEARCHED PERIOD AND INCORPORATES GEOGRAPHICAL LOCATION AS A RELEVANT FACTOR THAT WAS NOT ANALYZED IN OTHER STUDIES, AND WHICH CONTRIBUTES TO EXPLAIN THE PROPOSED MODEL. AMONG THE IMPLICATIONS OF THE STUDY, IT IS CLEAR THAT RESULTS ALLOW MANAGERS AND FIRMS' OWNERS TO UNDERSTAND THE ELEMENTS THAT INFLUENCE ORGANIZATIONAL RESULTS, CONSIDERED THE BASIS OF THEIR EXISTENCE AND SURVIVAL IN THE FUTURE.

MODELS WITH TIME-VARYING PARAMETERS HAVE BECOME MORE POPULAR FOR TIME SERIES ANALYSIS. AMONG THESE MODELS, GENERALIZED AUTOREGRESSIVE SCORE (GAS) MODELS ARE BASED ON THE SPECIFICATION OF THE MECHANISM THROUGH WHICH PAST OBSERVATIONS OF THE VARIABLE OF INTEREST AFFECT THE CURRENT VALUE OF THE TIME-VARYING PARAMETERS. GAS MODELS ALLOW CAPTURING THE DYNAMIC BEHAVIOR OF TIME SERIES PROCESSES, WHICH IS AN ADVANTAGE OVER MODELS SUCH AS ARMA AND GARCH WITH FIXED PARAMETERS. IN THIS PAPER, WE EXTEND THE DISTRIBUTION SETTING OF GAS MODELS FROM CLASSICAL DENSITIES TO SINH-ARCSINH (SAS) ONES, WITH EMPHASIS ON SAS-GAUSSIAN AND SAS-T DISTRIBUTION. THE SAS FAMILY PROVIDES FLEXIBLE DISTRIBUTIONS THAT ALLOW MODELING THE ASYMMETRY AS LIGHT OR HEAVY TAILED. THE PARAMETERS OF THE FAMILY ENABLE CLEAR INTERPRETATIONS, AND LIMITING DISTRIBUTIONS ARE ESPECIALLY APPEALING AS SHAPE PARAMETERS TEND TO THEIR EXTREME VALUES. THE PROPOSED METHOD?S PERFORMANCE IS ILLUSTRATED IN SIMULATIONS AND A REAL-WORLD APPLICATION TO A FISH CONDITION DATASET. IN CONCLUSION, THE SAS-GAUSSIAN DISTRIBUTION FITS THE DATASET BEST BY FAR.

THE IMPACT OF GENDER ON CORPORATE EARNINGS IS A SUBJECT OF INTEREST IN THE ACADEMIC AND ORGANIZATIONAL WORLD. THEREFORE, THE OBJECTIVE OF THIS ARTICLE IS TO DETERMINE THE IMPACT THAT OCCURS ON BUSINESS RESULTS FROM THE PRESENCE OF MEN AND WOMEN IN THE OWNERSHIP AND MANAGEMENT OF COMPANIES. FOR THIS WORK, THE RESEARCH DESIGN IS NOT EXPERIMENTAL - DOCUMENTARY, WITH A KIND OF EXPLANATORY STUDY, THE CONTRASTATION IS PERFORMED ON TWO PANELS OF CHILEAN INDUSTRIAL COMPANIES, USING A SECONDARY SOURCE OF INFORMATION CALLED ANNUAL NATIONAL INDUSTRIAL SURVEY (ENIA) FOR THE PERIOD 2001 -2007. WITH DESCRIPTIVE ANALYSIS WAS DISCOVERED THAT COMPANIES GET SIMILAR RESULTS, INDIFFERENT TO THE GENDER OF THE OWNERS, UNLIKE THE SAMPLE OF MANAGERS, WHERE IT IS OBSERVED THAT WOMEN OBTAIN BETTER BUSINESS RESULTS AND APPLYING TECHNIQUES OF PANEL DATA, IT DISCOVERED THAT THE OWNER?S GENDER HAS AN IMPACT ON THE RESULTS OBTAINED, BEING POSITIVE IN THE CASE OF MEN AND NEGATIVE IN THE CASE OF WOMEN. THE USEFUL AND NOVELTY OF THIS STUDY IS APPLIED TO A DEVELOPING COUNTRY, BECAUSE THE MAJORITY OF THIS TYPE OF ANALYSIS ADDRESSES THE DEVELOPED COUNTRIES.

AN EXTENSION OF THE GENERALIZED AUTOREGRESSIVE SCORE (GAS) MODEL IS PRESENTED FOR TIME SERIES WITH EXCESS NULL OBSERVATIONS TO INCLUDE EXPLANATORY VARIABLES. AN EXTENSION OF THE GAS MODEL PROPOSED BY HARVEY AND ITO IS SUGGESTED, AND IT IS APPLIED TO PRECIPITATION DATA FROM A CITY IN CHILE. IT IS CONCLUDED THAT THE MODEL PROVIDES ADEQUATE PREDICTION, AND FURTHERMORE, AN ANALYSIS OF THE RELATIONSHIP BETWEEN THE PRECIPITATION VARIABLE AND THE EXPLANATORY VARIABLES IS SHOWN. THIS RELATIONSHIP IS COMPARED WITH THE METEOROLOGY LITERATURE, DEMONSTRATING CONCURRENCE.

BACKGROUND GIVEN THE RELEVANCE OF SOCIAL SUPPORT ON THE MENTAL HEALTH OF OLDER ADULTS, HAVING AN INSTRUMENT TO EVALUATE THIS VARIABLE IS ESSENTIAL FOR RESEARCH IN THE AREA. HOWEVER, MAINLY, HAVING INSTRUMENTS WITH SUITABLE EVIDENCE OF THEIR PSYCHOMETRIC PROPERTIES IS CRITICAL. FOR THIS REASON, THIS STUDY SOUGHT TO EVALUATE THE FACTORIAL AND RELIABILITY STRUCTURE OF THE MULTIDIMENSIONAL SCALE OF PERCEIVED SOCIAL SUPPORT WITHIN AUTONOMOUS OLDER ADULTS FROM THE PROVINCE OF CONCEPCION, CHILE. METHODS WE SURVEYED 399 OLDER ADULTS USING QUOTE SAMPLING. THEY ANSWERED A SPANISH VERSION OF THE MULTIDIMENSIONAL SCALE OF PERCEIVED SOCIAL SUPPORT, PLUS A SOCIODEMOGRAPHIC QUESTIONNAIRE. WE PERFORMED CONFIRMATORY FACTOR ANALYSIS USING WEIGHTED LEAST SQUARES MEANS AND VARIANCES ADJUSTED ESTIMATION (WLSMV) TO COMPARE THE FACTOR MODELS PROPOSES BY PREVIOUS STUDIES. TO EVALUATE RELIABILITY, WE CALCULATED CRONBACH'S ALPHA AND MCDONALD'S OMEGA. RESULTS THE CONFIRMATORY FACTOR ANALYSIS FOUND THAT THE 3-FACTORS MODELS SHOWED THE BEST FIST INDEX BETWEEN THE MODELS WITH CFI = 0.991, TLI = 0.989, AND SRMR = 0.035, EVEN THOUGH RMSEA WERE OVER THE CUTOFF POINT. THE FACTORS PRESENTED RELIABILITIES FROM ALPHA = 0.858 TO ALPHA = 0.941, AND FROM OMEGA = 0.937 TO OMEGA = 0.972. CONCLUSIONS THE RESULTS SUPPORT THE EXISTENCE OF THREE FACTORS FOR THE MULTIDIMENSIONAL SCALE OF PERCEIVED SOCIAL SUPPORT (MSPSS), DIFFERENTIATING THE SUPPORT PERCEIVED FROM FAMILY, FRIENDS, AND SIGNIFICANT OTHERS. ALL FACTORS PRESENT GOOD OR EXCELLENT RELIABILITY. THIS SOLUTION IS THEORETICALLY CONSISTENT AND COHERENT WITH THE LITERATURE, AND IT PRESENTS EVIDENCE IN FAVOR OF THE USE OF MSPSS AS A MEASUREMENT TO DISTINGUISH THE SUPPORT PERCEIVED SOURCE.

IN THIS WORK, WE USE A COINTEGRATION STATE SPACE APPROACH TO ESTIMATE THE QUARTERLY SERIES OF THE CHILEAN GROSS DOMESTIC PRODUCT (GDP) IN THE PERIOD 1965?2009. FIRST, THE EQUATION OF ENGLE?GRANGER IS ESTIMATED USING THE DATA OF THE YEARLY GPD AND SOME RELATED VARIABLES, SUCH AS THE PRICE OF COPPER, THE EXPORTS OF GOODS AND SERVICES, AND THE MINING PRODUCTION INDEX. THE ESTIMATED COEFFICIENTS OF THIS REGRESSION ARE THEN USED TO OBTAIN A FIRST ESTIMATION OF THE QUARTERLY GDP SERIES WITH MEASUREMENT ERRORS. A STATE SPACE MODEL IS THEN APPLIED TO IMPROVE THE PRELIMINARY ESTIMATION OF THE GDP WITH THE MAIN PURPOSE OF ELIMINATING THE MAXIMUM ERROR OF MEASUREMENT SUCH THAT THE SUM OF THE THREE-MONTH VALUES COINCIDE SWITH THE YEARLY GDP. THE RESULTS ARE THEN COMPARED WITH THE TRADITIONAL DISAGGREGATION METHODS. THE RESULTING QUARTERLY GDP SERIES REFLECTS THE MAJOR EVENTS OF THE HISTORICAL CHILEAN ECONOMY.

A TWO-WEEK-LONG INTERVENTION STUDY WAS PERFORMED IN TWO CLASSROOMS IN AN ELEMENTARY SCHOOL IN COSTA RICA. SPLIT-COOLING AIR-CONDITIONING (AC) UNITS WERE INSTALLED IN BOTH CLASSROOMS. DURING THE FIRST WEEK, THE AIR TEMPERATURE WAS REDUCED IN ONE CLASSROOM WHILE IN THE OTHER (PLACEBO) CLASSROOM THE FANS WERE OPERATED BUT NO COOLING WAS PROVIDED. DURING THE SECOND WEEK, THE CONDITIONS WERE EXCHANGED TO CREATE A 2 × 2 CROSSOVER DESIGN IN WHICH EACH PUPIL WAS THEIR OWN CONTROL. A TOTAL OF 37 CHILDREN PERFORMED TASKS SIMILAR TO SCHOOL WORK AND COMPLETED QUESTIONNAIRES REPORTING THEIR THERMAL SENSATION AND PERCEPTIONS. OPERATING THE AC UNITS REDUCED CLASSROOM TEMPERATURE BY ABOUT 5 K, FROM ABOUT 30 TO 25°C. THERMAL SENSATIONS CHANGED FROM HOT TO NEUTRAL AND SLIGHTLY COLD, AND THE PERCENTAGE OF CHILDREN RATING THE THERMAL CONDITIONS AS ACCEPTABLE INCREASED SIGNIFICANTLY. NEUTRAL TEMPERATURE WAS ESTIMATED TO BE ABOUT 27°C. THE 11-YEAR-OLD CHILDREN PERFORMED THE LANGUAGE AND LOGICAL-THINKING TASKS SIGNIFICANTLY BETTER IN TERMS OF SPEED AT THE LOWER TEMPERATURE, WHILE THE LESS ABLE PUPILS PERFORMED BETTER ON ALL TASKS AT THE LOWER TEMPERATURE. THERE WERE NO SIGNIFICANT EFFECTS ON ACCURACY. THESE RESULTS CONFIRM PUBLISHED FINDINGS FROM MODERATE CLIMATES AND EXTEND THEIR VALIDITY TO THE TROPICS. THEY INDICATE THAT ACCLIMATIZATION CAN INCREASE THE OPTIMAL TEMPERATURE FOR LEARNING.