Em um certo mercado, a demanda inversa é dada por P = 100 - Q, em que P é o preço do produto e Q a quantidade total demandada. Suponha que o efeito-renda é nulo. A oferta do bem é dada por P = Q. Julgue a afirmativa a seguir:

Item 4: Se, em vez do imposto, o governo cria um subsídio de s = 20 por cada unidade comercializada, então haverá um ganho de bem-estar dado por G = 100.

Inflation in emerging economies - An old enemy rears its head

(From The Economist print edition , May 24th 2008)

EVEN as America's economy teeters on the brink of recession and many European economies are slowing, central bankers in rich countries fear rising inflation. Yet the risks they face are smaller than those in emerging economies, where inflation has risen far more over the past year to its highest for nine years. There are also an alarming number of similarities between developing economies today and developed economies in the early 1970s, when the Great Inflation took off. Are the young upstarts heading for trouble?

The text implies that:

Considere uma economia aberta, descrita pelas seguintes funções consumo, investimento, exportações líquidas e demanda por moeda:

C = 100 + 0,6Y.

I = 50 – 4i.

NX = 50 + 0,1Y* – 0,1Y + 70ε.

(M/P)^d = 0,5Y/i.

Em que Y é o produto doméstico, Y* = 1.000 é o produto externo, i é a taxa de juros doméstica e ε é a taxa de câmbio real. Os gastos do governo são G = 100; os níveis dos preços interno e externo são iguais a P = P* = 1; a taxa de juros externa é i* = 5. Há livre mobilidade de capitais. O governo deste país adota um regime de câmbio fixo (com taxa de câmbio nominal igual a 1) e não há expectativa que esta paridade será alterada no futuro. Julgue a seguinte afirmativa:

Item 2: A oferta nominal de moeda M é de 120.

Some countries look more prone to rising inflation than others. From an analysis of wages, inflation expectations, demand and capacity pressures, and monetary growth, Mr Cates infers that Argentina, Brazil, India, Russia and the Middle East oil exporters face the biggest risks in the months ahead. Pressures seem less great in China, Mexico, South Korea and Turkey.

Clearly, monetary policy needs to be tightened. Instead, it has in effect been loosened: real interest rates are generally lower than they were a year ago. Short-term interest rates are also unusually low relative to nominal GDP growth a crude gauge of where rates should be, which implies that monetary policy is very loose (...). The broad money supply has grown by an average of 20% over the past year in emerging economies, almost three times the pace in the developed world (…). Russia's money supply has swelled by fully 42%.

Add all this up, and emerging economies bear strong similarities to rich countries in the 1970s, when the Great Inflation took off. A synchronised boom in the world economy has caused commodity prices to surge. Governments have responded with subsidies and wage and price controls. Official statistics understate price pressures. Economies are running at full pelt. Money-supply growth is soaring. Inflation expectations are not anchored and labour markets are fairly rigid, increasing the risk of a spiral in wages and prices.

According to conventional wisdom, the monetary-policy mistakes that caused the Great Inflation are much less likely today because central banks are independent of politicians. But unlike the Federal Reserve and the European Central Bank ECB, many central banks in emerging economies notably China, India and Russia are not fully independent. In another echo of the 1970s, they often face intense political pressure to hold rates low to boost growth and jobs.

The text remarks on:

Item 1: the recent soaring of commodities prices;

Verifique se a afirmativa abaixo é verdadeira

Item 3: Seja X₁,X₂,....,X_n uma amostra aleatória simples proveniente de uma população com distribuição de Pareto cuja função densidade é dada por !$ f(x) θ(1 + x)^{-(θ+1)} !$, !$ 0 < x < \infty !$, !$ θ > 1 !$. Então o estimador de máxima verossimilhança para !$ θ !$ é !$ { \large n \over \sum log(1 + x_i)} !$.

É correto afirmar que:

Item 3: O processo AR(2), !$ y_t = Φ_0 + Φ_1y_{t-1} + Φ_2y_{t-2} + e_t !$, em que !$ e_t !$ é um ruído branco de média nula e variância !$ σ^2 !$, será estacionário de segunda ordem se, e somente se, !$ Φ_1 < 1 !$ e !$ Φ_2 < 1 !$.