Therefore, it would be preferable to have even more frequent data on poverty and inequality than at a five year interval. Since collecting household survey data is costly and time-consuming, annual data collection can be burdensome for many National Statistics Offices (NSOs) and data quality could suffer as a result. We are aware that recent innovations in survey data collection and imputation techniques allow us to fill the data gaps with less cost and time. However, the reliability of such techniques also depends on the availability and frequency of traditional household consumption surveys.

Considering the necessity to monitor the progress of poverty reduction reliably, keeping in mind data quality, and looking at data from 2002-11, the latest 10 year interval for which we can infer reliable statistics on data availability, we classify countries into five categories:

- i) Countries with **extreme data deprivation** in monitoring poverty are those without any poverty data point in the ten year reference period. These countries would require the strongest efforts to reach the benchmark of two data points in any ten year interval.

- ii) Countries with **moderate data deprivation** are those with one data point in any ten year interval. iii) Countries that are **vulnerable to data deprivation** are those with two data points in 2002-11, but at an interval of more than five years apart. These countries are at risk of falling short of having adequate data for poverty monitoring (as they will not have two poverty data points in _any_ ten year interval).

- iv) Countries with two data points in ten years with the surveys 5 years apart are deemed to satisfy **a minimum requirement for data needs.**

- v) Countries with 3 or more data points in any 10 year interval are considered to be **satisfactory for data needs** .

Note that while the above classification is prepared by frequency of poverty data, we have also attempted to incorporate the notion of ‘regularity’ in defining countries that are vulnerable to data deprivation. Regularity of data collection is, however, a somewhat amorphous concept to measure when looking at a 10 year time period. For example, even if poverty data of one country are available in 2005 and 2010, it is difficult to infer that this country collects poverty data _every_ five years. The possibility, that this country collected data in 2005 and 2010 but will not collect poverty data in 2015, remains.<sup>9</sup> To see whether a country collects data every five years, we could increase the time period, for example to a 20 year period. Since for most countries, poverty data are not available prior to 1990, such measures are difficult to obtain and we remain at a 10 year time period to measure data frequency and regularity.

# **Global trends**

Using the classification suggested above and looking at the 2002-11 time period, we see that 63 of 155 countries have satisfactory data availability with three or more data points and 15 countries meet the minimum requirement for data needs with two data points with 5 year intervals (Figure 3). Clearly, over time the number of countries with satisfactory data availability has increased. At the same time, countries with extreme data deprivation have declined (from 50 in 1990-99 to 29 in 2002-11).

> 9 Jordan, e.g., conducted its flagship household survey in two year intervals between 2006 and 2010 followed by a 4 year interval.

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