oversight can add red tape, rather than cutting it. It can further a compliance- rather than performanceattitude among staff. Second, the entry of a third player can undermine line-agencies ownership of the procurement process and dilute responsibility. When contract implementation and monitoring quality of delivered products are in the hands of the end-user public bodies efficiency gains achieved by central framework agreements can be undermined as end-users may not be willing or able to fully enforce centrally set contractual terms (Albano & Zampino, 2012). Third, standardization can imply that the needs of end users are not fully met. Inflexible standard tender documents may cause complications if they do not fit the needs of a particular contract. Fourth, demand aggregation and the implied larger contracts also concentrate potential corrupt rents raising the attractiveness of agency capture. Fifth, larger contracts may prevent smaller companies from bidding which is likely to drive prices up if there are not enough large companies willing to bid.

# _b) Evidence_

Evidence on collaborative procurement is very limited with a handful of qualitative or small-N quantitative studies with the exception of a UK government report (National Audit Office, 2010), while centralized procurement, especially on the national level, received somewhat more thorough scholarly interest. Unfortunately, neither streams of literature allow for drawing solid conclusions for policy makers.

Qualitative and quantitative studies looking at collaborative procurement practices in the UK and Australia have found that different organizational forms of collaborative procurement perform strikingly differently in distinctive contexts for different types of procuring bodies (Bakker et al., 2008; Barbosa & Fiuza, 2012; Ey et al., 2014; Walker et al., 2013). For example, the level of standardization of the products purchased and user needs define the scope for savings achievable with collaborative procurement: e.g. office stationery versus defense procurement (National Audit Office, 2010).

A high quality quasi-experimental study aiming to estimate the amount of passive and active waste (that is low administrative capacity versus corruption) in Italian standardized goods purchases also touches on the effect of central framework agreements. It finds that centralized purchasing of standard goods such as office stationery achieved a 34%-78% price reduction according to the invoices paid by procuring bodies reaping the benefits of demand aggregation as the central agency can save on transaction costs and has more buyer power that can be exploited to obtain lower prices (Bandiera et al., 2009). Considerably dampening the positive expectations, another Italian study looking at the implementation of the centralized framework agreements by receiving public bodies found that roughly one-third of procuring bodies (30.75%) received products in substantial breech of contractual terms (Albano & Zampino, 2012). More alarmingly, a negligible portion of these procuring bodies have actually issued a penalty to the supplier according to the contract (2.49%). Taken together, such findings highlight the potential for savings through centralized procurement with the risks carried by dissociating tendering and contract management.

Examining the case of CONSIP in Italy, Decarolis (2018), using procurement data on all public contracts awarded between 2015 and 2017, finds that administrations expecting to lose their ability to contract independently game the centralization requirements in three ways. In the short run, they anticipate their purchases to avoid delegating to a central body. In the longer run, they both manipulate contract values, breaking down purchases into smaller lots of amounts below the thresholds driving centralization requirements, and, when given the option, aggregate into the smallest types of centralized purchasing bodies. These three distortions partially offset the potential benefits of the centralization reforms (Decarolis, 2018).

Another study using a unique dataset on tender prices of selected drugs for hospital usage provided by a sample of 52 Italian local health service providers between 2009 and 2012 tests which procurement system (centralized, decentralized or hybrid) performs better. Controlling for several covariates, including measures of institutional quality and corruption, it finds that centralized and hybrid procurers pay lower 21