Considerando uma solução !$ x(t) !$ qualquer da equação diferencial !$ 3\cdot x"(t)+4 \cdot x'(t)+x(t)=0 !$, assinale V (verdadeiro) ou F (falso)

Item 3 - se !$ x(t) !$ é tal que !$ x(0)=0 !$ e !$ x'(0)=1 !$ então !$ lim_{t \rightarrow -\infty} x(t)=-\infty !$;

Um monopolista cujos custos de produção são dados por !$ c(q)=q^2+100 !$ defronta-se com a demanda de mercado !$ p=A-3q !$, em que A > 0 é uma constante. É correto afirmar:

Item 3 - Considerando A = 48, um regulador que estipule um preço mínimo de R$ 30,00 estará agindo conforme o interesse do monopolista de maximizar lucro em detrimento do ótimo social.

Responda V (verdadeiro) ou F (falso):

Item 4 - Seja !$ f:\mathbb{R} \rightarrow \mathbb{R} !$ uma função estritamente côncava tal que !$ f(0) < f(1) !$. Então !$ f !$ é estritamente crescente no intervalo [0,1].

The Origins of Structuralism

H.W. Arndt. Modern Political Economy and Latin America. Eds. Jeffry Frieden,
Manuel Pastor Jr., and Michael Tomz. Westview Press, 2000: 5-9.

Introduction

In his recent book on economic development, I.M.D. Little distinguishes two broad categories of development economics. He calls them ‘neoclassical economics’ and ‘structuralism’.

“The structuralist sees the world as inflexible. Change is inhibited by obstacles, bottlenecks and constraints. People find it hard to move or adapt, and resources tend to be stuck. In economic terms, the supply of most things is inelastic. Such general inflexibility was thought to apply particularly to LDC’s.... Entrepreneurs were lacking; and communications were poor.... This alleged inflexibility was married to the evident fact that the production structure of developing countries was very different from that of developed countries. To achieve development, it had to be changed rapidly.... The structuralist view of the world provides a reason for distrusting the price mechanism and for trying to bring about change in other ways. If supplies and demands are very inelastic large price changes are needed to achieve small quantitative adjustments. Large price changes are disturbing, both directly and also because they result in changes in income distribution.... If the losers are powerful, they may... be able to resist the change through organized industrial or political action... Structuralism primarily seeks to provide a reason for managing change by administrative action.”

The purpose of this article is to explore further the origins of structuralism, both in the broader sense and the more specific context of Latin American structuralist theories of inflation, and the links between them.

According to the same author, structuralism rests on the following assumptions:

Item 1 - skewed distribution of land ownership,

Considerando a função !$ f(x,y)=2\cdot x^2+x \cdot y^2+y^2 !$, assinale V (verdadeiro) ou F (falso):

Item 4 - !$ f(x,y) < x^2 + x \cdot y^2+1 !$ para !$ x^2+y^2 < 1 !$.

Considere a seguinte regressão entre!$ y_t !$ e !$ z_t !$:

!$ y_t=\alpha z_t + u_t !$,

em que !$ u_t !$ é o erro. É correto afirmar:

Item 4 - Se !$ u_t !$for I(0) as séries !$ y_t !$ e !$ z_t !$ são necessariamente co-integradas.

Sejam !$ X_1, X_2, ..., X_n !$ variáveis aleatórias independentes e normalmente distribuídas com média !$ \mu !$ e variância !$ \sigma^2 !$. Em relação ao teste de hipótese da média 00:!$ H_0:\mu = \mu_0 !$ contra !$ H_a:\mu < \mu_0 !$, é correto afirmar:

Item 3 - A função-potência para este teste de hipótese será uma função decrescente da média !$ \mu !$.