Avalie o item abaixo, relativas ao modelo clássico (também chamado neoclássico) e ao modelo IS-LM:

Item 2 - Um deslocamento para a direita da função poupança (no plano S, i), no modelo clássico, provoca uma redução dos juros. O mesmo ocorrerá no modelo IS-LM, em resposta a um deslocamento para a esquerda da função poupança (no plano Y, S), desde que a LM seja positivamente inclinada.

Para mercados em concorrência perfeita, é certo o item:

Item 3 - No equilíbrio de longo prazo, informação perfeita e livre entrada de agentes no mercado garantem que lucros anormais sejam insustentáveis.

Research outputs apart, the very structure of agricultural research is changing in response to the needs and demands of wealthy farmers, consumers, and researchers. It is well known that biotechnology is concentrated mainly on the products, conditions, and factor intensities of big Western farmers. This, and similar trends in other areas of agricultural research, threatens to substantially reduce the proportion of research devoted to the farm products, labor intensities, and local resource degradation threats that concern smallholders in poor countries. All this provides exogenously structured incentives (and funds) for international and national agricultural research systems that do not focus on reducing the rate of resource degradation in developing rural areas.

The following statements summarize some of the main ideas presented in the text:

Item 3 - Resource degradation in rural areas is enhanced by market failures.

Com relação a testes de hipótese, é correto afirmar que:

Item 3 - em um modelo de regressão linear utiliza-se um teste bilateral para verificar se determinado coeficiente é estatisticamente diferente de zero;

Considere um modelo de sinalização do tipo Spence no qual os trabalhadores escolhem um nível de educação. Há uma grande quantidade de firmas e de trabalhadores. Os trabalhadores hábeis têm a função de utilidade !$ U_H=w-{\large{3 \over 8}}E^2 !$ e os trabalhadores pouco hábeis têm a função de utilidade !$ U_{PH}=w-{\large{1 \over 2}}E^2 !$, em que w representa o nível salarial e E o nível educacional. Um trabalhador hábil com nível de educação EH vale 1,5EH para a firma, enquanto um trabalhador pouco hábil com nível de educação EPH vale1EPH. Metade dos trabalhadores são hábeis. Julgue o item:

Item 4 - Caso haja um equilíbrio separador, nele, ter-se-á !$ E^*_H > \large{3+\sqrt 5 \over 2} !$ ou !$ E^*_H < \large{3- \sqrt 5 \over 2} !$.

Many authors attribute much resource degradation in developing rural areas (DRAs) to market failure and policy failure – failure, in each case, to “reflect environmental values.” Other authors attribute much resource degradation to incorrect domestic policies affecting relative prices. This chapter suggests, instead, that most resource degradation in DRAs responds to the success of domestic markets and policies. They succeed in communicating to rationally maximizing agents (households, firms, managers of common property) that changes in prices (especially real interest rates) and in technical options increasingly favor accelerated resource degradation.

According to the text, much of natural resource degradation in developing rural areas (DRAs) has been (or can be) attributed to:

Item 2 - relative prices distorting policies;

Indeed, accelerated resource degradation in DRAs is mainly the cumulative consequence of developed country policies that have led to (1) a tripling of world real interest rates between 1945-1974 and 1979-1993, and in the longer term, (2) falling and unstable relative farm prices, and (3) labor-displacing technical progress. In this chapter I set out reasons for believing that these international effects have been paramount.

In its analysis of the causes of natural resource degradation in DRAs, the text

Item 4 - blames the farmers in developing rural areas for the adoption of labor-displacing technical progress.

Therefore, if one focuses on choices in resource management – for example between various levels of water use or between nutrient cycling and mining – it becomes impossible to miss the powerful resource-depleting incentive created by higher real interest rates. Costly credit undoubtedly shifts the composition – of inputs, outputs, techniques, investments, consumption, and savings, - sharply in a resource-depleting direction. It is only the effect of costly credit on degradation via investment levels that remains in doubt.

According to the text, higher real rates of interest have a powerful resource-depleting influence because they

Item 2 - favor nutrient mining over nutrient cycling;