Problemas de Mensuração na Presença de Inflação Alta e Variável:

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1 Curso Bem-Estar Social Marcelo Neri Problemas de Mensuração na Presença de Inflação Alta e Variável: 1) A alta instabilidade de renda superestima as medidas de desigualdade. Mudanças na variabilidade temporal da renda que de alguma afetam o nível de bem estar (por outros canais) também afetam de maneira espúria a comparação de medidas de desigualdade, em particular aquelas baseadas em dados de rendas mensais. 2) Deflatores de renda na presença de inflação alta, variável e com mudanças de moeda. Isto só afeta o nível de renda e não a desigualdade. Nota: Além dos cortes de zero há que se tomar cuidado com o carry-over. Por exemplo, as séries do INPC tem de inflacionadas em mais 21,99% na introdução do Real. No longo prazo, há que se notar os vieses para cima de índices de base fixa que não incorporam efeitos substituição. 3) Deflatores diferenciados por tipo de renda em termos de data de recebimento. Neste caso o processo de deflação afetaria também a desigualdade. 4) Relacionado ao ponto anterior temos o padrão temporal de gastos da renda. Em particular, na presença de alta inflação ocorre a incidência de perdas decorrentes do Imposto Inflacionário. High inflation makes measured earnings very sensitive to timing assumptions implicit in deflating procedures. We deal now with two of the deflation related problems mentioned above: 3) it uses available payment's period information to deflate earnings at the time they are paid. 4), the paper evaluates the size of inflationary losses incurred in the interval between earnings are paid and spend. 3) Deflação Diferenciada i) The payments periods A.Employees Payments Periods PME has information on the payment's frequency of employees previous month main income source. There are four possible answers in PME questionnaire: Monthly payments, Biweekly payments, Weekly payments and Other forms of payments. Vide gráficos 1, 2, 22 e 23 B.Self-Employed and Employers Payments Periods While PME has direct information on employees payment's periods, no such information is available for employers and self-employed individuals. However, employers and self-employed individuals, function as firms selling their products and services directly in the market throughout the month. Therefore, employers and self-employed incomes are received on average in the middle of the month. Corresponding one should also use a deflator with the same date. Vide gráficos 3 e 4 1

2 Figure 4 illustrates possible effects of the bias incurred by not considering payments dates information. It shows the evolution of the simple average across metropolitan regions of the relation between the average's monthly earnings of self-employed and employers, on the one hand, and employees with monthly payments, on the other. For short, I call this relation O/1. O/1, as presented in figure 4, is not corrected for existing lags between its numerator and denominator. Perhaps, the main problem with this bias is not constant but it oscillates with inflation. Figure 4 also shows that inflation rates have been high and erratic in the recent Brazilian experience. Much of this instability is due to the launching of unsuccessful stabilization policies (ie. heterodox plans). A visual inspection of figure 4 shows: 1)Five sharp inflation drops followed by increases in the nominal earnings ratio 0/1. 2)Except for the first drop in inflation in 1986, the ratio 0/1 is close to a local minimum just before these inflation drops. The combination between the rise in inflation observed before the stabilization plans and the posterior fall in inflation explain these local minimum. 3)Perhaps more interesting the 0/1 ratios assume an inverted U-shaped pattern after these points that follow the cycle of fall and rise of inflation rates. ii)payments Period and Timing Adjustments in Deflating Procedures The price index used in income deflating procedures is the National Consumer Price Index for families with incomes lower than eight minimum wages (INPC) from IBGE. The INPC of month t (INPC t ), reflects the price information of four weekly samples, starting at the first day of the same month. Table I below presents a link between the INPC and the payments period information discussed in the previous section: Table 1 Payments Group - Average Pay Day - Price Deflator Monthly - 30 (INPC t-1 ) 1/2. (INPC t ) 1/2 Bi-weekly (INPC t-1 ) 3/4. (INPC t ) 1/4 Weekly (INPC t-1 ) 11/12. (INPC t ) 1/12 Employers and Self-Employed - 15 INPC t-1 Table 1 assumes that incomes are received after the work is done. The use of individual payments period information according to Table 1 above, when compared with a uniform deflation centered at the end of the month, generated in the to period the following results: 1)a reduction of the bias imputed in self-employed and employers average earnings of 10.97% across the six PME metropolitan regions. 2)A reduction of the average bias introduced in employees earnings of 0.86% across the six PME metropolitan regions. These results suggest that the simple procedure of deflating self-employed and employer incomes with a price index centered in the middle of the month can eliminate most of the measurement error observed in wage differentials between working classes. On the other hand, the inconvenience of using individual information on employees payments frequency might not compensate for the small reduction of measurement error observed. A less precise but much simpler alternative to deflate aggregate employees' earnings is to 2

3 center consumer price indexes around the average payments dates for the to period. 4) The Inflation Tax Effect This table develops a model following inventory deterministic approach to evaluate inflation tax losses incurred in the interval between labor income is paid and spend. According to the model, individuals choose the optimal number of trips to the banks and to the shops and consequently their respective stocks of money, bonds and commodities, as follows: during the interval between the receipt and the expenditure of income, consumers attempt to maximize their financial profit obtained from cash management procedures. Individuals distribute their consumption evenly throughout this period (but not their expenditures!) to exhaust their resources just before next payment. The representative consumer's asset options are: Currency (M); Short term financial assets (T), Consumers Goods (Q's). Ver tabela simulando o modelo e gráfico apresentando o contraste das perdas inflacionárias para a alta e a baixa renda. Vide Tabela e gráfico 9 3

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