单项选择题

Russian president Vladimir Putin has inadvertently (不注意地) spotlighted one of today’’s momentous mysteries: collapsing birthrates in industrialized countries. Putin proposed that Russia pay women to have children to remedy a "critical" population outlook. Actually, he might have said "desperate." In 2000, Russia’’s population totaled almost 147 million. Russia’’s case, though extreme, isn’’t isolated. There’’s no more population "explosion." In wealthier countries, motherhood is going out of style and plunging birthrates portend population loss. One way or another, the side effects will be massive for economics, politics and people’’s well being. Indeed, they may already have started. Is it a coincidence that Germany and Italy, two countries on the edge of population decline, are so troubled First, some facts. On average, women must have two children for a society to replace itself. The actual number of children per woman is called the "total fertility rate," or TFR. Here are the 2005 TFRs for some major countries: Germany, 1.4; Greece, 1.3; Italy, 1.3; Japan, 1.4; Poland, 1.2; and Russia, 1.3. Low fertility rates don’’t instantly lead to population declines. They can be offset by immigration, longer life expectancies and greater numbers of young mothers. But ultimately, low fertility rates suggest falling populations. "The forthcoming and dramatic depopulation of Europe and Japan will cause many problems," writes Ben Wattenberg in "Fewer," his excellent book on the subject. "Populations will age, the customer base [for businesses] will shrink, there will be labor shortages, the tax base will decline, pensions will be cut, retirement ages will increase." Up to a point, we understand plunging fertility rates. The usual suspects: improved incomes; health and life expectancies (as more children survive, parents have fewer babies); growing urbanization (families need fewer children to work the fields); women’’s access to education and jobs; contraception; later and fewer marriages; more divorces. But our understanding is only partial, because there’’s one big exception to low fertility rates: the United States. American fertility is roughly at the replacement rate, 2.1 children per woman. Nor does the U.S. rate merely reflect, as some think, a higher rate among Hispanic Americans. The fertility rate is 1.9 for non-Hispanic whites and about 2 for African-Americans, reports demographer Nicholas Eberstadt of the American Enterprise Institute. What explains the American exception Eberstadt cites three differences with Europe and most other advanced countries: greater optimism, greater patriotism and stronger religious values. Indeed, generous welfare states may discourage having children. A study by economists at the University of Minnesota found that high Social Security payments and payroll taxes are associated with low fertility rates. People may feel they don’’t need children to care for them in old age. Or high taxes and poor economies may deter young people from starting families. According to the passage, if a country wants to increase its population, it__________.