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Thelargeramachineandthemorenumerousitsparts,thegreaterlikelihoodofabreakdownandthemoreexpensivetorepair．Whathasbeensaidaboutmarketforcesandmanagementwasnecessarilyoversimplified．Theeconomiesofmodernindustrialnationsarelargeandverycomplex.Tobesure,thereismanagement,andtherearemarketforcesatwork,buttherearealsomanyotherfactorsthathelporhindereconomicfunction.
Inmodemindustrialsocieties,governmentsplayalargerole．Thereisagreatamountofregu-
lation,mostofitmeantfortheprotectionofthepublic．Allregulationsaffectthewaybusinessesoperate,oftenincreasingtheircostsandreducingtheirprofits．Lowerprofits,inturn,reducetheamountofmoneywhichis.knownasworkingcapitalthatacompanycanuseforexpansion．Autoe-missionstandards,forinstance,havehadasignificantimpactonthemanufactureandpricingofautomobiles．Othergovernmentpoliciessuchastaxation,budgetdeficits,andregulationofthemoneysupplyhaveaneffectonhowmuchmoneyisavailableforpeopletospendongoodsandservices.
Internationalcrisesandotherconditionsalsoaffecttheworkingofaneconomy．AseverefrostinBrazilcanruinacoffeecropandraisethepriceofthatcommodity．Warcancutoffthesupplyofsuchresourcesaspetroleum,chromium,orcopper．IntheUnitedStatesenvironmentalprotestshaveslowedthedevelopmentofnuclearenergycapacityandtheminingofvasttractsofprotectedland．Weatheraffectsagriculture,ahot,drysummercandamagethewheatcrop;floodscande-stroythousandsofacresofcropssuddenly;andinsectpestscandevastatecroplandwitharapidonslaught.
People'sattitudesalsohaveanimpactonthemarketingofgoods．Health-consciousindividu-als,forexample,maystopsmoking,curtailtheirintakeofalcohol,andeatlessofcertainkindsoffood．Advertisingaffectswhatpeoplebuy,anditcancreateamarketwherenoneexisted．Styleandfashionaresignificantformanyconsumers.
Thereareothereconomicproblemsthataremoredifficulttounderstand．Forcenturiese-conomieshavebeensubjecttoperiodsofprosperityfollowedbyperiodsofdecline．Althoughperi-odsofprosperitycanbeexplainedrathereasily,thereasonsforpanics,recessions,anddepres-sionsareofacomplexnature．SomanyfactorscontributedtotheGreatDepressionofthe1930s,forexample,thatnoeconomisthaseverbeenabletoaccountforallofthem.
Becausethecausesofdeclineareuncertain,theremediesareequallyuncertain．Inthelate20thcenturyallindustrializedsocietiesthroughtheirgovernmentshavetriedtostabilizee-conomies,keepthemprosperous,andreduceunemployment．Noneoftheremedieshasworkedtotheextentthatwashoped．Howeconomiesworkandwhatremediescanbefoundtokeepthemop-eratingefficientlyarethetasksofeconomists,whomustworktogetherwithbusinessmenandpoliticians.
Thechiefpurposeofthepassageis__________ A．toreviewthefactorsthataffecteconomicoperation
B．toexplorethecausesofperiodiceconomicdecline
C．todiscusstherolegovernmentsplayinmodernindustrializedsocieties
D．toproposeremediesforcorrectingeconomicrecessions
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