Answer the following question based on this news article from the New York Times:

"By nearly any economic measure, India is a poor country, but precisely how poor? The attempt to answer that question has sparked a vigorous debate in recent months among some of the country's leading economists. The question is not purely academic. Recent government surveys - including a big one released last week - have not produced solid data about whether poverty has declined in the 1990's, when the state loosened its grip on the economy and opened the door to international trade. The statistical muddle has made it difficult to judge whether faster economic growth and increased spending on anti-poverty programs have, in fact, bettered the lot of the poor. Poverty is tricky to measure and India's recent experience is an object lesson in the complexities of the task. In the National Sample Survey Organization's previous large-scale survey of 120,000 households, conducted in 1993 and 1994, investigators asked people how much food they had consumed in the prior 30 days. So in subsequent years, while conducting smaller annual surveys, one group of households was asked how much they had eaten in the previous 30 days and another what they had eaten in the prior 7 days. The difference was staggering. In 1998, for example, the rate of poverty in the households that answered the 30 day question was 39.9 percent; the rate for those who answered the 7 day question was 22.6 percent." What is the most likely explanation for the difference in the two reports - a 30-day report and a 7-day report? Provide a thorough explanation