Foram encontradas 395 questões.
Suponha que queremos estimar como a renda de um indivíduo varia ao longo do ciclo de vida. Queremos testar a teoria de que a renda do indivíduo cresce a partir do momento que ele entra no mercado de trabalho até uma idade média, e depois começa a decrescer até o final do ciclo de vida. Usando dados de uma pesquisa anual para 14.368 trabalhadores, estimamos o seguinte modelo:
!$ Y_i=\beta_0+\beta_1X_{1i}+\beta_2X_{2i}+\beta_3X_{3i}+\beta4X_{1i}\,^2+ε_i !$,
em que !$ Y_i !$ é o logaritmo da renda mensal do indivíduo i, !$ X_{1i} !$ é a idade do indivíduo i, !$ X_{2i} !$ é uma variável binária que é igual 1 se o indivíduo é homem e !$ X_{3i} !$ representa o número de anos de estudo do indivíduo i.
Estimando o modelo por Mínimos Quadrados Ordinários, obtemos o seguinte resultado, em que os valores em parênteses abaixo dos coeficientes representam os erros-padrão: [Para a resolução desta questão talvez lhe seja útil saber que se Z tem distribuição normal padrão, então P(|Z|>1,645)=0,10 e P(|Z|>1,96)=0,05]

Item 2 - O resultado indica que, mantendo tudo mais constante, o aumento de 1 ano da idade do indivíduo aumenta a sua renda em 45%;
Provas
Questão presente nas seguintes provas
Considere o seguinte sistema de equações lineares de oferta e demanda de trabalho das mulheres casadas. Neste sistema, as duas variáveis endógenas, salário (P) e quantidade de horas trabalhadas (Q), são determinadas pela educação (!$ X_1 !$), idade (!$ X_2 !$), número de filhos (!$ X_3 !$) e dois termos não-observáveis !$ (ε_{1i}, ε_{2i}) !$.
Demanda: !$ Q_i=\alpha_1P_i+\alpha_2X_{2i}+\alpha_3X_{3i}+ε_{1i} !$
Oferta: !$ P_i=\alpha_4Q_i+\alpha_5X_{1i}+\alpha_6X_{2i}+ε_{2i} !$
Temos uma amostra aleatória de N mulheres, !$ (Q_i,P_i,X_{1i},X_{2i},X_{3i}) !$, !$ i=1, \cdots, N !$.Vamos assumir que a matriz !$ [X_1,X_2,X_3] !$ tem posto completo.
Julgue o item abaixo:
Item 1 - Podemos escrever a curva de oferta na sua forma reduzida como:
!$ P_1= ∅_1X_{1i}+∅_2X_{2i}+∅_3X_{3i}+\vartheta_{2i} !$
em que !$ ∅_1=\large{\alpha_5 \over 1- \alpha_4 \alpha_1} !$, !$ ∅_2=\large{\alpha_2 \alpha_4+\alpha_6 \over 1- \alpha_4 \alpha_1} !$, !$ ∅_3=\large{\alpha_3 \alpha_4 \over 1- \alpha_4 \alpha_1} !$ e !$ \vartheta_{2i}=\alpha_4 \varepsilon_{1i}+\varepsilon_{2i} !$. Se assumirmos que !$ E[\varepsilon_{1i} \mid X_{1i}, X_{2i},X_{3i}]=0 !$ e !$ E[\varepsilon_{2i} \mid X_{1i}, X_{2i}, X_3i}]=0 !$, o estimador de Mínimos Quadrados Ordinários para !$ ∅_2 !$ será um estimador consistente;
Provas
Questão presente nas seguintes provas
Text 2
India
Can India become a great power?
India’s lack of a strategic culture hobbles its ambition to be a force in the world
(from The Economist print edition, March 30th-April 5th 2013)
NOBODY doubts that China has joined the ranks of the great powers: the idea of a G2 with America is mooted, albeit prematurely. India is often spoken of in the same breath as China because of its billion-plus population, economic promise, value as a trading partner and growing military capabilities. All five permanent members of the United Nations Security Council support—however grudgingly—India’s claim to join them. But whereas China’s rise is a given, India is still widely seen as a nearly-power that cannot quite get its act together.
That is a pity, for as a great power, India would have much to offer. Although poorer and less economically dynamic than China, India has soft power in abundance. It is committed to democratic institutions, the rule of law and human rights. As a victim of jihadist violence, it is in the front rank of the fight against terrorism. It has a huge and talented diaspora. It may not want to be co-opted by the West but it shares many Western values. It is confident and culturally rich. If it had a permanent Security Council seat (which it has earned by being one of the most consistent contributors to UN peacekeeping operations) it would not instinctively excuse and defend brutal regimes. Unlike China and Russia, it has few skeletons in its cupboard. With its enormous coastline and respected navy (rated by its American counterpart, with which it often holds exercises, as up to NATO standarAlternativa India is well-placed to provide security in a critical part of the global commons.
The modest power
Yet India’s huge potential to be a force for stability and an upholder of the rules-based international system is far from being realised. One big reason is that the country lacks the culture to pursue an active security policy. Despite a rapidly rising defence budget, forecast to be the world’s fourth-largest by 2020, India’s politicians and bureaucrats show little interest in grand strategy (…). The foreign service is ridiculously feeble—India’s 1.2 billion people are represented by about the same number of diplomats as Singapore’s 5m. The leadership of the armed forces and the political-bureaucratic establishment operate in different worlds. The defence ministry is chronically short of military expertise.
These weaknesses partly reflect a pragmatic desire to make economic development at home the priority. India has also wisely kept generals out of politics (a lesson ignored elsewhere in Asia, not least by Pakistan, with usually parlous results). But Nehruvian ideology also plays a role. At home, India mercifully gave up Fabian economics in the 1990s (and reaped the rewards). But diplomatically, 66 years after the British left, it still clings to the post-independence creeds of semi-pacifism and “non-alignment”: the West is not to be trusted.
India’s tradition of strategic restraint has in some ways served the country well. Having little to show for several limited wars with Pakistan and one with China, India tends to respond to provocations with caution. It has long-running territorial disputes with both its big neighbours, but it usually tries not to inflame them (although it censors any maps which accurately depict where the border lies, something its press shamefully tolerates). India does not go looking for trouble, and that has generally been to its advantage.
Indispensable India
But the lack of a strategic culture comes at a cost. Pakistan is dangerous and unstable, bristling with nuclear weapons, torn apart by jihadist violence and vulnerable to an army command threatened by radical junior officers. Yet India does not think coherently about how to cope. The government hopes that increased trade will improve relations, even as the army plans for a blitzkrieg-style attack across the border. It needs to work harder at healing the running sore of Kashmir and supporting Pakistan’s civilian government. Right now, for instance, Pakistan is going through what should be its first transition from one elected civilian government to the next. India’s prime minister, Manmohan Singh, should support this process by arranging to visit the country’s next leader.
China, which is increasingly willing and able to project military power, including in the Indian Ocean, poses a threat of a different kind. Nobody can be sure how China will use its military and economic clout to further its own interests and, perhaps, put India’s at risk. But India, like China’s other near neighbours, has every reason to be nervous. The country is particularly vulnerable to any interruption in energy supplies (India has 17% of the world’s population but just 0.8% of its known oil and gas reserves).
(...)
According to the text:
Item 3 - Pakistan, like India, has kept generals out of politics;
Provas
Questão presente nas seguintes provas
Text 2
India
Can India become a great power?
India’s lack of a strategic culture hobbles its ambition to be a force in the world
(from The Economist print edition, March 30th-April 5th 2013)
NOBODY doubts that China has joined the ranks of the great powers: the idea of a G2 with America is mooted, albeit prematurely. India is often spoken of in the same breath as China because of its billion-plus population, economic promise, value as a trading partner and growing military capabilities. All five permanent members of the United Nations Security Council support—however grudgingly—India’s claim to join them. But whereas China’s rise is a given, India is still widely seen as a nearly-power that cannot quite get its act together.
That is a pity, for as a great power, India would have much to offer. Although poorer and less economically dynamic than China, India has soft power in abundance. It is committed to democratic institutions, the rule of law and human rights. As a victim of jihadist violence, it is in the front rank of the fight against terrorism. It has a huge and talented diaspora. It may not want to be co-opted by the West but it shares many Western values. It is confident and culturally rich. If it had a permanent Security Council seat (which it has earned by being one of the most consistent contributors to UN peacekeeping operations) it would not instinctively excuse and defend brutal regimes. Unlike China and Russia, it has few skeletons in its cupboard. With its enormous coastline and respected navy (rated by its American counterpart, with which it often holds exercises, as up to NATO standarAlternativa India is well-placed to provide security in a critical part of the global commons.
The modest power
Yet India’s huge potential to be a force for stability and an upholder of the rules-based international system is far from being realised. One big reason is that the country lacks the culture to pursue an active security policy. Despite a rapidly rising defence budget, forecast to be the world’s fourth-largest by 2020, India’s politicians and bureaucrats show little interest in grand strategy (…). The foreign service is ridiculously feeble—India’s 1.2 billion people are represented by about the same number of diplomats as Singapore’s 5m. The leadership of the armed forces and the political-bureaucratic establishment operate in different worlds. The defence ministry is chronically short of military expertise.
These weaknesses partly reflect a pragmatic desire to make economic development at home the priority. India has also wisely kept generals out of politics (a lesson ignored elsewhere in Asia, not least by Pakistan, with usually parlous results). But Nehruvian ideology also plays a role. At home, India mercifully gave up Fabian economics in the 1990s (and reaped the rewards). But diplomatically, 66 years after the British left, it still clings to the post-independence creeds of semi-pacifism and “non-alignment”: the West is not to be trusted.
India’s tradition of strategic restraint has in some ways served the country well. Having little to show for several limited wars with Pakistan and one with China, India tends to respond to provocations with caution. It has long-running territorial disputes with both its big neighbours, but it usually tries not to inflame them (although it censors any maps which accurately depict where the border lies, something its press shamefully tolerates). India does not go looking for trouble, and that has generally been to its advantage.
Indispensable India
But the lack of a strategic culture comes at a cost. Pakistan is dangerous and unstable, bristling with nuclear weapons, torn apart by jihadist violence and vulnerable to an army command threatened by radical junior officers. Yet India does not think coherently about how to cope. The government hopes that increased trade will improve relations, even as the army plans for a blitzkrieg-style attack across the border. It needs to work harder at healing the running sore of Kashmir and supporting Pakistan’s civilian government. Right now, for instance, Pakistan is going through what should be its first transition from one elected civilian government to the next. India’s prime minister, Manmohan Singh, should support this process by arranging to visit the country’s next leader.
China, which is increasingly willing and able to project military power, including in the Indian Ocean, poses a threat of a different kind. Nobody can be sure how China will use its military and economic clout to further its own interests and, perhaps, put India’s at risk. But India, like China’s other near neighbours, has every reason to be nervous. The country is particularly vulnerable to any interruption in energy supplies (India has 17% of the world’s population but just 0.8% of its known oil and gas reserves).
(...)
According to the text:
Item 4 - There is no widespread acknowledgement of China's position as a great power.
Provas
Questão presente nas seguintes provas
A respeito das funções utilidades e seus vários formatos, podemos afirmar:
Item 3 - A função !$ U(x,y)=min(\alpha x, \beta y) !$; !$ \alpha !$, !$ \beta > 0 !$ é tal que pessoas que se comportam segundo essa função estão dispostas a dar a mesma quantidade de y por uma unidade adicional de x, não importando quanto de x já tenha sido consumido;
Provas
Questão presente nas seguintes provas
O processo de industrialização foi objeto de interpretações e intenso debate. Sobre o processo de industrialização e suas interpretações é correto afirmar que:
Item 2 - há autores que defendem que, antes de 1930, os períodos considerados como de maior aumento de investimento na indústria não coincidiam com os surtos de maior aumento da produção industrial.
Provas
Questão presente nas seguintes provas
A função !$ f(x,y)=kxy^2 !$, !$ k > 0 !$, está definida no conjunto !$ C=\{(x,y) ∈ R^2/0 \le x \le1,(x/2) \le y \le x\} !$. Avalie a seguinte asserção:
Item 2 - Considere !$ k=1 !$. Para cada !$ y ∈ [0,1] !$ definimos o conjunto !$ C_y=\{x ∈[0,1]/(x,y) ∈ C \} !$ e a função !$ f_Y(y)=\int\limits_{C_y}f(x,y)dx !$. Então !$ {\large{f_Y(3/4) \over f_Y(1/4)}}=2,33 !$.
Provas
Questão presente nas seguintes provas
Julgue o item abaixo:
Item 3 - Suponha que Y seja uma variável aleatória distribuída de acordo com a função densidade: f(y)=2y-3, em que y≥1. Então a mediana de Y é !$ \sqrt 2 !$;
Provas
Questão presente nas seguintes provas
Com relação a externalidades é possível afirmar:
Item 1 - Se a curva de indiferença dos indivíduos assume a forma !$ x_2=k-\nu(x_1) !$, então toda solução eficiente terá a mesma quantidade de externalidades;
Provas
Questão presente nas seguintes provas
Com relação à teoria dos bens públicos, indique se o item abaixo é certo ou errado:
Item 0 - Para determinar o nível eficiente de oferta de um bem público é necessário igualar a soma dos benefícios marginais dos usuários do bem público ao custo marginal de sua produção;
Provas
Questão presente nas seguintes provas
Cadernos
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