For those of us preoccupied with the study of crime in Mexico, there is one great frustration. That official statistics are often unreliable and sometimes by design.

It presents a monumental challenge, especially when we are accumulating the data for the 2016 Mexico Peace Index, released today, which provides a comprehensive measure of levels of violence in the country from 2003 to 2015. So how do we know when official statistics are wrong?

At the Institute for Economics and Peace we took the homicide numbers as recorded by the police and compared them to the numbers of death certificates certified by medical professionals that list murder as the cause of death. In doing so, we found that homicide victims have been undercounted by law enforcement agencies by more than 20 percent in 11 Mexican states. They are troubling figures.

This is an op-ed by Steve Killelea, chairman and founder of the Institute for Economics and Peace, which publishes the Mexico Peace Index. It does but not necessarily reflect the views of InSight Crime. See our take on the index here

In 2014, every Mexican state had at least a small discrepancy between police and medical data sources. Some amount of difference is to be expected, as some of the cases investigated by police may have been found to not be homicides upon review by a coroner, but the sizes of some of the gaps raise concerns about the veracity of data provided by law enforcement agencies. In the state of Veracruz, for example, only 63.9 percent of the homicide victims recorded in death certificates in 2014 were the subject of police homicide investigations.

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In addition, during our research we found that only around 10 percent of extortions, 17 percent of rapes and 32 percent of kidnappings are reported to authorities.

Disappearances are a problem in Mexico as well, with accounts of the discoveries of mass graves, such as those in Guerrero, and loved ones searching for their missing. The official numbers say that more than 26,000 people are known to have gone missing in Mexico since 2007, which is incomplete. That figure only represents the people who are currently missing, it does not represent the total number of all the people who have gone missing in that time given that some have reappeared or been found dead.

In our in-depth analysis on disappearances in Mexico, we can see that the majority of the people reported and currently missing are male youths, and are often working class men with families. Their disappearances, while tragic in themselves, can have a serious impact on the financial circumstances of extended families.

Corruption is an issue in Mexico and its manifestations and extent vary from state to state, leading in some cases to underreporting of data. There has been a problematic relationship between organized crime, some government operations and law enforcement in Mexico since at least the 1990s, leading to its place at the lowest ranking on the Corruption Perceptions Index of any OECD country. This raises concerns that law enforcement agencies may not be investigating all cases or that official agencies could be deliberately underreporting the level of crime within jurisdictions in order to appear more efficient and lawful.

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Meanwhile, 60 percent of victims, when surveyed and asked why they didn’t report a crime to the authorities, said it was due to the performance of government agencies.

Changes are underway, however. Mexico is investing in police, judicial and penal system reforms, including the New Criminal Justice System (NSJP), the implementation deadline for which is in June 2016. This will allow defendants to challenge prosecution evidence more effectively, and should reduce trial times, sometimes by years. It will also establish the presumption of innocence to accused parties, guarantee their right to a licensed public defender, and prohibit torture, intimidation and incommunicado detention. As of March 2014, the public security secretariat has also been required by law to publish victim counts for the investigations into homicide, kidnapping and extortion, a requirement that represents an advancement in efforts towards transparency.

In the meantime, how do we compensate for the poor quality of the official figures? IEP’s analysis takes into account a number of sources, public surveys and the wisdom of an expert panel, and adjusts government data to account for underreporting.

It’s with this depth of scrutiny that the latest edition presents a cautiously optimistic picture for the future of peace in Mexico, although efforts need to be made to strengthen the capacity of government agencies, including in their recording of crime statistics. Accurate data is important. Because with it can come an understanding of the scale of problems, the policies that work, the trends, patterns and drivers of peace. All of which can allow a society to gain the wisdom needed to implement a long-lasting and meaningful peace.

*Steve Killelea is the chairman and founder of the Institute for Economics and Peace, which publishes the Mexico Peace Index.

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