به اشتراک گذاری کیک ملی پس از اصلاحات نیوزیلند : روند نابرابری درآمد در شرایط منابع درآمد

Using Household Economic Survey (HES) data in unit record form, this paper examines the trends of household income inequality in New Zealand over the period 1984–96, a period that saw New Zealand implement a wide range of economic and social policy reform. The observed changes in the overall income inequality are then decomposed by income components to measure the contributions of the different sources of personal income to the overall inequality. To our knowledge, this is the first time that the methodology for disaggregating the Gini co-efficient, including its more recent extensions by Lerman and Yitzhaki [Review of Economics and Statistics 63 (1985) 151]; Podder [Review of Income and Wealth 39 (1993) 51]; and Mookherjee and Shorrocks [Economic Journal 92 (1982) 886], has been applied to micro-level New Zealand data for computing income inequality and other, related, indices and measures reported in this study. The findings, which indicate a steady upward trend in income inequality, are examined in the light of the reform policies used at the time. Their implications for policy are also addressed.

This paper investigates the recent trends in New Zealand’s income distribution, and examines empirically the sources from which the observed increases in income inequality have stemmed. The period between 1984 and 1996 – the period of this study – saw New Zealand implement a wide range of economic and social policy reforms. These reforms involved, inter alia, the deregulation and/or privatization of many previously state-controlled activities; freeing-up of the financial market, capital flows and the exchange rate; removal or reduction of trade barriers, reform of the tax system and other fiscal arrangements; fundamental alterations to the laws governing the labour market and industrial relations; granting of formal autonomy to the central bank, and reductions in many social welfare benefit payments as part of an overall policy of reduced government involvement in the economy and society. There is a growing body of literature examining the policies used by New Zealand, and their outcome. The interested reader in referred to the article by Evans et al. (1996) and the collection of studies edited by Silverstone et al. (1996) for a detailed overview. Although a definitive verdict on the reform programme to date is yet to be delivered, it is frequently hailed as a successful experiment (Henderson 1996; Evans et al., 1996) which offers many useful lessons for other countries facing a policy quandary similar to New Zealand’s in the early 1980s. The underlying aim of the reform programme, it would be useful to remember, was primarily to shift the policy emphasis from stabilisation and equity, a long-established tradition in New Zealand’s public policy-making, and focus economic efficiency (Bollard, cited in Kelsey, 1995, p. 53). Naturally enough, the policies used have affected the lives and livelihoods of many New Zealanders in major ways. However, the question as to who benefited how much from the reform measures is one that has not, as yet, been adequately addressed. A major test of any economic policy measure is how it affects the size of the ‘national cake’, i.e. the nation’s real income, and its growth rate. A second, related, test is how it affects the manner in which the ‘cake’ is divided up amongst different groups in society. It is this latter issue that the present paper addresses. The study is based on unit record data from the Household Expenditure and Income Surveys (HEIS) for 1983/84, and 1991/92, and the Household Economic Survey (HES) for 1995/96, specially made available at our request by Statistics New Zealand, 1999, Statistics New Zealand, 1996, Statistics New Zealand, 1994 and Statistics New Zealand, 1984, 1992. Several other studies have addressed the issue of inequality and income distribution in New Zealand (Bakker, 1996; Barker, 1996; Creedy, 1996 and Creedy, 1997; and Easton, 1996, for example) in recent years, but without the use of unit record data. There are also the studies that have examined inequality mainly from a labour market perspective. The study by Winkelmann and Winkelmann (1998) for example examines the labour market outcomes, in terms of employment and incomes, for immigrants in New Zealand with the help of data primarily from the 5- or 10-yearly population censuses between 1981 and 1996. This study does not look at the distribution of incomes as such, but at the income differentials within immigrant groups, and between specified categories of immigrants and native-born New Zealanders. Dixon (1996) is concerned with the distribution of individual earnings. Within its narrow focus, it concentrates “on the market allocation of gross waged and salaried earnings, rather than the distribution of gross and net incomes across the population as a whole” (p. 46). This study too found that the inequality in wage and salary incomes increased significantly over the period 1986–96. The present study is thus the first wide-ranging study of income distribution and inequality in New Zealand using the data in its most disaggregated form. A Statistics New Zealand (Stats NZ) report (1999) on income trends, published a few months after ours, has also used unit record data in estimating inequalities from various angles. We report some of its findings in appropriate contexts below. The main finding of our study is that, not only has the overall inequality sharply increased in recent years, but the pattern of the distribution of income has also changed in an interesting way. It is only the use of unit record data that has enabled us to quantify and explain with precision the sources of the observed overall income inequality. As is well known, the Gini coefficient of total income measures the overall degree of inequality. However, the total income of a person or a household is usually made up of a number of components, as income may be received from various sources. The manner in which the different types or components of income are distributed is likely to explain the overall inequality in the distribution of the total income. For example, many believe that incomes received from investment are a greater source of inequality in total income than are wages and salaries. Likewise, it is a widely held perception that spouse’s earnings introduce a higher degree of inequality in the distribution of total household incomes. Alternative sets of income components could be conceived depending on one’s interest. For example, if we are interested in the sources of income, we can consider a set of components such as wage income, interest and dividend, and so on. Again, we could distinguish ‘earned income’ from investment income, sometimes referred to as ‘unearned income’. Irrespective of the way total income is disaggregated, one should be able, in an ideal situation, to determine the exact contribution of each of the components to the overall inequality. Failing that, at least it should be possible to study the sensitivity of the overall degree of inequality with respect to any changes in each of the components. Both for policy purposes and for the investigation of the sources of inequality, disaggregation of the overall inequality by factor components is of crucial importance. However, the very meaning of the word ‘contribution’ in this context is subject to controversy. In this paper we first examine critically the different interpretations to which the notion of the contribution of a factor has been subjected, and then investigate what can be achieved with the help of the Gini coefficient when it is disaggregated by factor components. Indeed, the subject needs particularly careful and meticulous treatment. This is because the disaggregation of inequality by factor components and, in particular, the disaggregation of the Gini coefficient is probably the most misused and misunderstood concept in the income inequality literature. As we shall see, it is the spread of a specific income component over the ranges of total income which determines whether that component causes overall inequality to increase or decrease. In addition, any changes in the sources of income affect the overall inequality in two different ways: through a change in the relative share of that income source; and through a change in the pattern of the spread of that income source over the ranges of total income. This latter change would affect the overall inequality even if the share remained unchanged. Understanding the sources from which the changes in the total inequality derive is crucially important for policy formulation in the area. In this paper we investigate the changes in the total income inequality in New Zealand over the period 1984–1996, and explain these changes in terms of those in the income components. The following section presents the method of analysis; Section 3 discusses the data set and the procedures for handling some related empirical issues. The fourth section presents the empirical results and their interpretations. The final section contains some concluding observations.

This paper has applied a new, and more sophisticated, technique to New Zealand household income data to examine how household income distribution has altered over the period 1983/84 through to 1995/96, using unit record data from three surveys. The use of the data at this level of detail by researchers outside Statistics New Zealand, 1999, Statistics New Zealand, 1996, Statistics New Zealand, 1994 and Statistics New Zealand, 1984, 1992 has never been possible (permitted) before. The findings of this paper, therefore, throw new light on several aspects of household income distribution in New Zealand over a period when the economy was subjected to an extensive reform process. The findings document that income inequality has increased sharply over the period, confirming the findings of some other researchers (Joseph Rowntree Foundation, 1995 and Saunders, 1994). While it is difficult to connect directly the economic reform measures used in New Zealand with the observed deterioration in inequality, the possible channels through which policy-induced changes in the economy might have been transmitted to the distribution of the ‘national cake’ can be, and have been, identified in this paper. The sharp increase in unemployment over the latter part of the 1980s and early 1990s while, again, not a direct cause of increased inequality, has certainly contributed to the process. Likewise, the distortions in the financial markets, which saw the nominal interest rates soar to unprecedented levels in the later 1980s and early 1990s, resulted in changes to household incomes in a way that, again, contributed to the increased inequality. Interestingly too, whatever the positive outcome of the changes in the tax-expenditure policies over the period of the reform, they contributed to increased income inequality. More significantly, perhaps, the drastic cuts in the welfare benefits put in place in 1991 despite being directed towards the poor somewhat better, failed to stem the tide of rising overall inequality because of the inadequacy of the transfers. The somewhat more stringent eligibility requirement for New Zealand superannuation, likewise, helped minimise the equalising impact of this component of income. It should also be remembered that the deregulation process in New Zealand coincided with the structural changes taking place in many other economies. The structural changes, influenced by the information revolution, have increased the demand for highly-skilled (high-wage) labour in a disproportionate manner. As a result, the inequality of earnings has increased sharply in many Western economies. Evidence on this is scanty for New Zealand, but some indirect indicators cited earlier do point to at least a possibility that skilled labour has gained in the course of the reform period. But, whatever the reasons, it is indeed a spectacular, if somewhat ironic, finding of this paper that the bottom 80% of New Zealand income recipients suffered a reduction in their share of the total incomes paid out, while the top 5% enjoyed a 25% gain after 12 years of painful restructuring. The share of the top 10% steadily increased to exceed that of the bottom half of the income-earned by 1996. There are, no doubt, other aspects of the story of New Zealand’s household income distribution that need addressing. The policy implications stemming from the findings also need careful examination. Meanwhile, the verdict on how well-off New Zealanders are after all the recent economic changes must remain an open issue.