NOTA METODOLOGICĂINDICELE PREŢURILOR DE CONSUM (IPC)METHODOLOGICAL NOTECONSUMER PRICE INDEX (CPI)Indicele preţurilor <strong>de</strong> consum (IPC) măsoarăevoluţia <strong>de</strong> ansamblu a preţurilor mărfurilorcumpărate şi a tarifelor serviciilor utilizate <strong>de</strong> cătrepopulaţie într-o anumită perioadă (perioadă curentă),faţă <strong>de</strong> o perioadă anterioară (perioadă <strong>de</strong> bază sau<strong>de</strong> referinţă). Indicele preţurilor <strong>de</strong> consum secalculează numai pentru elementele care intră înconsumul direct al populaţiei, fiind excluse:consumul din resurse proprii, cheltuielile cu caracter<strong>de</strong> investiţii şi acumulare, dobânzile plătite la credite,ratele <strong>de</strong> asigurare, amenzile, impozitele etc., precumşi cheltuielile aferente plăţii muncii pentru producţiaagricolă a gospodăriilor individuale.Sursele <strong>de</strong> date1. Înregistrarea preţurilor şi tarifelor practicate <strong>de</strong>unităţile comerciale sau prestatoare <strong>de</strong> servicii serealizează printr-o cercetare selectivă organizată <strong>de</strong><strong>Institutul</strong> Naţional <strong>de</strong> Statistică. Colectarea datelor,asigurată <strong>de</strong> personal statistic specializat, seefectuează pe baza unor caiete-chestionarcorespunzătoare grupelor <strong>de</strong> mărfuri (alimentare,nealimentare) şi servicii. Cercetarea statistică asuprapreţurilor <strong>de</strong> consum utilizează următoareleeşantioane:i) Eşantionul <strong>de</strong> localităţi - stabilit cu respectarearestricţiilor <strong>de</strong> reprezentativitate în funcţie <strong>de</strong> numărul<strong>de</strong> locuitori şi <strong>de</strong> volumul <strong>de</strong>sfacerilor <strong>de</strong> mărfuri şi alprestărilor <strong>de</strong> servicii. Acesta cuprin<strong>de</strong> 42 <strong>de</strong> localităţidin mediul urban din care au fost selectate 68 <strong>de</strong>centre <strong>de</strong> cercetare.ii) Eşantionul unităţilor <strong>de</strong> observare - cuprin<strong>de</strong>magazine şi unităţi prestatoare <strong>de</strong> servicii cătrepopulaţie din centrele <strong>de</strong> cercetare. Selecţia s-abazat pe necesitatea asigurării reprezentativităţii dinpunct <strong>de</strong> ve<strong>de</strong>re al volumului <strong>de</strong>sfacerilor <strong>de</strong> mărfurişi al prestărilor <strong>de</strong> servicii. Unităţile în care seînregistrează preţurile/tarifele sunt menţinute îneşantion, pe cât posibil, o perioadă mai mare pentrua asigura continuitatea şi comparabilitatea în timp aseriilor <strong>de</strong> date. Eşantionul cuprin<strong>de</strong> circa 7100 <strong>de</strong>unităţi din care aproape 87% sunt proprietate privată.Preţurile/tarifele stabilite prin acte normative saunote <strong>de</strong> negociere (energie termică, gaz metan şipreţuri/tarife unice pe ţară pentru energie electrică,transport pe calea ferată, aeriană şi fluvială, servicii<strong>de</strong> corespon<strong>de</strong>nţă şi curierat, abonamente radio-TV)The consumer price in<strong>de</strong>x measures the overallevolution of prices for goods bought and for tariffs ofservices used by the population during a certainperiod (current period), as against a previous period(basic or reference period). The consumer price in<strong>de</strong>xis calculated only for the elements entering thepopulation direct consumption, excluding:consumption from own resources, expenditures forinvestments and accumulation, interests paid forcredits, insurance rates, fines, taxes etc., as well asexpenditures paid for the agricultural production ofindividual households.Data sources1. The prices and tariffs used by commercial units andby units providing services are registered by means ofa sampling survey carried out by the <strong>National</strong>Institute of Statistics. The specialized statistical staffensures the data collection based on questionnairebookscorresponding to the groups of goods (foodand non-food) and services. The statistical survey onconsumer prices uses the following samples:i) Sample of localities - is established observing therestrictions of representativity <strong>de</strong>pending on thenumber of inhabitants and the volume of goodssales and provisions of services. It inclu<strong>de</strong>s 42localities from the urban area in which 68 researchcenters were selected.ii) Sample of observation units - inclu<strong>de</strong>s shops andunits ren<strong>de</strong>ring services to the population fromresearch centers. The selection was based on theneed to ensure the representativity from the viewpointof the volume of goods sales and provisions ofservices. The units in which prices / tariffs arerecor<strong>de</strong>d are kept in the sample, as much as possible,for a longer period of time in or<strong>de</strong>r to ensure thecontinuity and comparability of data series over time.The sample inclu<strong>de</strong>s about 7100 units of which 87%represent private ownership.The prices/tariffs established by normativedocuments or negotiation notes (thermal energy,methane gas, and unique prices/tariffs by country forelectric energy, rail, air and river transport, mail andcourier services, radio and TV subscriptions) are5
sunt înregistrate pe baza informaţiilor primite <strong>de</strong> launităţile care le practică.iii) Eşantionul <strong>de</strong> mărfuri şi servicii - cuprin<strong>de</strong>sortimente care au o pon<strong>de</strong>re semnificativă înconsumul populaţiei. Nomenclatorul utilizat estestructurat pe 3 nivele <strong>de</strong> agregare: grupe, posturi şisortimente astfel:- grupa mărfurilor alimentare cuprin<strong>de</strong> 54 posturi cu395 sortimente;- grupa mărfurilor nealimentare cuprin<strong>de</strong> 111 posturicu 977 sortimente;- grupa serviciilor cuprin<strong>de</strong> 49 posturi cu 448sortimente.Sortimentele se individualizează în teren prin varietăţi<strong>de</strong> mărfuri şi servicii.2. Informaţiile colectate prin această cercetare suntcompletate cu cele provenite din cercetarea privindpreţurile principalelor produse agricole vândute<strong>de</strong> producătorii particulari pe pieţeleagroalimentare, asigurându-se astfel acoperireaprincipalelor surse <strong>de</strong> aprovizionare a populaţiei.Sistemul <strong>de</strong> pon<strong>de</strong>rarePon<strong>de</strong>rile utilizate pentru calculul indicilor preţurilor<strong>de</strong> consum sunt obţinute din Ancheta Bugetelor <strong>de</strong>Familie (ABF) şi rezultă din structura cheltuielilormedii lunare efectuate <strong>de</strong> o gospodărie pentrucumpărarea bunurilor şi pentru plata serviciilornecesare satisfacerii nevoilor <strong>de</strong> trai. Periodic seanalizează structura cheltuielilor efectuate <strong>de</strong>populaţie, iar când mutaţiile intervenite suntsemnificative, pon<strong>de</strong>rile se actualizează. Astfel,începând din ianuarie 2012 în calculul IPC seutilizează pon<strong>de</strong>rile rezultate din structura cheltuielilormedii efectuate <strong>de</strong> o gospodărie în anul 2010.Metoda <strong>de</strong> calcul a IPCIPC se calculează ca un indice <strong>de</strong> tip Laspeyres cubază fixă. Începând din ianuarie 2012, calcululindicilor lunari cu bază fixă se va face cu preţurilemedii din anul 2010 (anul 2010=100) şi pon<strong>de</strong>riledin acelaşi an <strong>de</strong>terminate pe baza cheltuielilormedii din Ancheta Bugetelor <strong>de</strong> Familie.Pentru asigurarea continuităţii seriilor <strong>de</strong> indiciconstruiţi cu baze diferite s-a utilizat un „coeficient <strong>de</strong>racordare“ care permite legarea (racordarea) seriei<strong>de</strong> indici lunari din anul 2012 cu bază 2010=100 laseria <strong>de</strong> indici cu bază 2009=100. Coeficientul <strong>de</strong>racordare s-a <strong>de</strong>terminat ca raport între un indice <strong>de</strong>registered based on the information received from theunits setting them.iii) Sample of goods and services - inclu<strong>de</strong>s items thathave an important weight in the populationconsumption. The nomenclature used is divi<strong>de</strong>d into 3aggregation levels: groups, positions and items asfollows:- the group of food goods contains 54 positions with395 items;- the group of non-food goods contains 111 positionswith 977 items;- the group of services contains 49 positions with448 items.The items are individualized in the field by varieties ofgoods and services.2. To the information collected through this survey isad<strong>de</strong>d the information resulting from the survey onthe prices for the main agricultural productssold by private producers on agro-food markets,thus covering the main supply sources of thepopulation.Weighting systemThe weights used to calculate the consumer priceindices are obtained from the Household BudgetSurvey (HBS) and result from the structure ofmonthly average expenditure of a household for thepurchase of goods and the payment of servicesnecessary for meeting the living needs. The structureof population expenditure is periodically analysed;when changes are significant, weights are updated.Thus, beginning with January 2012, the CPI iscalculated using the weights resulted from thestructure of a household average expenditure in 2010.CPI computation methodThe CPI is calculated as a Laspeyres-type in<strong>de</strong>xwith a fixed base. Beginning with January 2012, themonthly indices with fixed base are calculated usingthe average prices of 2010 (2010 = 100) and theweights of the same year resulting from the averageexpenditure i<strong>de</strong>ntified by the Household BudgetSurvey.With a view to ensuring the continuity in the indicesseries built up with different bases, a “junctioncoefficient” was used, enabling the linking (junction) ofthe 2012 series of monthly indices (2010 = 100) to theindices series with the base 2009 = 100. The junctioncoefficient was calculated as a ratio between a6